Global Geopolitical Fragmentation, Energy Market Stress,
and a Bayesian Game-Theoretic Scenario Assessment
Macroeconomic Trajectories for the United States, Europe, East Asia, the Middle East, Latin America, and Sub-Saharan Africa amid the Strait of Hormuz Crisis
June 20, 2026
Executive Summary
As the G20 enters the second half of 2026, the global economy is being shaped less by a single crisis than by the interaction of several simultaneous ones: an unresolved war between the United States and Iran whose ceasefire architecture is being tested in real time, a new and assertive monetary policy posture at the U.S. Federal Reserve under incoming Chair Kevin Warsh, a euro area that has just resumed raising interest rates to defend its inflation target, and an OECD growth outlook that now hinges explicitly on how long Persian Gulf energy disruptions persist. This report extends and updates an earlier preliminary assessment in light of verified developments through June 20, 2026, and offers G20 policymakers a Bayesian, game-theoretic framework for interpreting how rational state and market actors are likely to update their beliefs — and their behavior — as the Hormuz situation evolves.
The most consequential development of the past several days is also the most fragile. On June 17, 2026, U.S. President Donald Trump and Iranian President Masoud Pezeshkian signed a memorandum of understanding in Versailles, on the margins of the G7 summit, establishing a sixty-day extension of the ceasefire and committing Iran to reopen the Strait of Hormuz while the United States lifted its naval blockade of Iranian ports. For roughly three days, the arrangement appeared to be holding: U.S. Central Command reported that dozens of merchant ships and many millions of barrels of oil resumed transiting the strait, and Vice President J.D. Vance described shipping conditions as having returned essentially to their pre-war baseline. On Saturday, June 20 — the date of this report — Iran's Revolutionary Guard Corps Navy announced that the strait was closed again, citing Israeli strikes in southern Lebanon that killed at least sixteen people, including children, as a violation of the broader ceasefire architecture that Tehran insists must cover all fronts, including Lebanon, even though Israel was not a direct signatory to the U.S.-Iran memorandum.
This single sequence — reopening, partial normalization, and renewed closure within the same week — is the clearest available illustration of the report's central analytical claim: the region has not moved from war to peace, but from open war to a condition of managed instability in which control over the Strait of Hormuz functions as a renewable instrument of coercive diplomacy. Iranian officials have been explicit on this point. An adviser to Iran's Supreme Leader stated publicly that energy flows through the Middle East will remain halted as long as the U.S.-Iran memorandum “remains only on paper,” while Tehran's state-aligned media has urged its negotiators not to arrive at talks in Switzerland “empty-handed.” The capacity to open and close a chokepoint carrying roughly one-fifth of the world's seaborne oil trade has become, in effect, Iran's principal source of negotiating leverage, deployed independently of its degraded conventional military capacity.
Financial markets are pricing this condition of recurring, reversible disruption rather than either durable peace or sustained war. Brent crude, which spiked above one hundred eighteen dollars per barrel in the first quarter of 2026 following the initial closure of the strait, has since retraced most of that increase and was trading near eighty dollars per barrel on June 19, even as the renewed closure was being announced — evidence that markets had already discounted a meaningful probability of exactly this kind of intermittent disruption rather than treating the June 17 memorandum as a clean resolution.
Two institutional forecasts anchor this report's macroeconomic baseline. The OECD's June 2026 Economic Outlook explicitly abandons a single-point forecast in favor of two named scenarios: a time-limited disruption scenario in which Persian Gulf energy production and exports normalize from the third quarter of 2026 onward, under which global growth slows from 3.4 percent in 2025 to 2.8 percent in 2026 before recovering to 3.1 percent in 2027; and a prolonged disruption scenario, in which disruptions persist into the second half of 2027, under which global growth falls to 2.1 percent in 2026 and 1.8 percent in 2027 — a slowdown the OECD characterizes as the deepest in four decades outside of the 2008–2009 financial crisis and the COVID-19 pandemic. This report's Bayesian scenario architecture is calibrated against, and extends, that institutional framework, while incorporating a third, more optimistic structured de-escalation path.
On monetary policy, the G20's two largest central banks have moved in the same hawkish direction but for related reasons. The Federal Reserve, in Kevin Warsh's first meeting as chair on June 17, held its benchmark rate at 3.50–3.75 percent but removed prior guidance toward a 2026 rate cut, with nine of eighteen policymakers now projecting at least one hike before year-end and the median dot implying a year-end rate of 3.8 percent — a full twenty-five basis points above the prior projection. The European Central Bank, on June 11, actually raised its three key rates by twenty-five basis points, lifting the deposit rate to 2.25 percent, and revised its 2026 growth projection down to 0.8 percent while lifting its headline inflation projection to 3.0 percent, explicitly attributing both moves to the war's effect on energy markets. Both decisions reflect a shared judgment that an energy-driven, supply-side inflation shock has reduced the room central banks have to support growth through lower rates, even as that same shock weakens the growth outlook each bank is mandated to support.
Section III of this report develops a Bayesian, game-theoretic forecast of growth, policy interest rates, and crude oil prices across six regions — the United States, the euro area, East Asia, the Middle East and North Africa, Latin America, and Sub-Saharan Africa — under three scenarios. Rather than presenting these as a static table, each regional and scenario-specific finding is developed analytically, with explicit attention to the belief-updating dynamics through which governments, central banks, and market participants revise their expectations as new information about the conflict arrives. The report's central conclusion is that the defining macroeconomic feature of the second half of 2026 will not be a single shock and recovery, but a prolonged equilibrium of managed instability, in which recurring, partially reversible disruptions to energy and shipping markets sustain an elevated and durable risk premium across global asset classes — a condition that calls for institutional resilience rather than crisis-by-crisis improvisation as the organizing principle of G20 economic policy coordination.
I. The Emerging Geopolitical Landscape: From Open War to Managed Instability
I.i. The Transition from Rules-Based Stability to Competitive Fragmentation
The post-Cold War assumption that economic interdependence would steadily reduce geopolitical competition has been challenged with growing force since 2022, and the events of 2026 have accelerated rather than reversed that trend. Major powers continue to pursue security-oriented economic strategies in which capital allocation, technology development, and energy procurement are organized increasingly around geopolitical alignment rather than pure market efficiency. The United States continues to prioritize technological sovereignty and strategic competition with China; China continues to pursue industrial self-sufficiency while expanding influence across the Global South; Europe continues to balance competitiveness against strategic autonomy; and Persian Gulf and other Middle Eastern powers increasingly act as independent strategic actors with their own bargaining leverage rather than passive participants in great-power competition. The result remains a gradual fragmentation of globalization rather than its wholesale reversal — but the Hormuz crisis of 2026 has demonstrated, with unusual clarity, how quickly fragmentation in one strategic domain (energy transit) can cascade into financial markets, inflation dynamics, and central bank policy across every G20 economy simultaneously.
I.ii. The Anatomy of the 2026 Iran War and Its Ceasefire Architecture
The conflict that has reshaped the 2026 global outlook began on February 28, 2026, when the United States and Israel launched air operations against Iran, including the killing of Iran's Supreme Leader, Ali Khamenei. Iran responded with missile and drone strikes against Israel, U.S. regional bases, and Persian Gulf states, and — critically for the global economy — the Islamic Revolutionary Guard Corps Navy began boarding and attacking merchant vessels and laying mines in the Strait of Hormuz, a waterway through which approximately one-quarter of the world's seaborne oil trade and one-fifth of global liquefied natural gas trade had passed before the war. The U.S. Energy Information Administration estimates that global oil supply fell by roughly thirteen and a half percent between February and April 2026, with Persian Gulf production down forty-five percent at the trough, while global gas supply is now expected to run approximately fifteen percent below pre-war projections given the halt of Qatari LNG exports following damage to production facilities.
What followed was not a single ceasefire but a sequence of fragile, repeatedly violated arrangements. An initial two-week ceasefire mediated by Pakistan in early April collapsed within days; a subsequent U.S. naval blockade of Iranian ports, paired with continued Iranian restrictions on the strait, kept the waterway effectively closed through most of the spring, with Abu Dhabi's national oil company reporting in April that some two hundred thirty loaded tankers were waiting inside Persian Gulf unable to depart. A further round of U.S. airstrikes on June 10, prompted by stalled negotiations, triggered another Iranian closure declaration before the two sides finally signed the more durable memorandum of understanding on June 17, at Versailles, on the margins of the G7 summit hosted by French President Emmanuel Macron.
The June 17 memorandum established a sixty-day window for negotiating final terms, during which Iran committed to reopening Hormuz and the United States agreed to lift its naval blockade of Iranian ports; President Trump stated separately that, absent a final agreement within that window, the United States could begin imposing tolls on shipping through the strait. For a brief period the agreement appeared to be functioning: U.S. Central Command reported fifty-five merchant ships transiting the strait on June 20 alone, carrying more than seventeen million barrels of oil, and Vice President Vance characterized conditions as having returned essentially to their pre-war baseline. Industry analysts cautioned, however, that mine-clearance operations alone could take weeks, meaning that even a fully cooperative reopening was always going to be a matter of gradual normalization rather than an immediate switch back to pre-war shipping patterns.
The reopening, partial normalization, and renewed closure of the Strait of Hormuz within a single week is the clearest available demonstration that the region has shifted from open war to a condition in which control over a single chokepoint functions as a renewable instrument of coercive diplomacy.
That brief normalization proved short-lived. On the morning of June 20, 2026 — the date of this report — Israeli strikes in southern Lebanon killed at least sixteen people, including two children, hours after a separate U.S.-brokered Israel-Hezbollah ceasefire had nominally taken effect. Iran's IRGC Navy responded within hours by declaring the Strait of Hormuz closed to all vessel traffic, warning ships that their safety could not be guaranteed and that mines remained a risk to any vessel that approached. Iran's military command characterized the closure explicitly as the "first step" in response to what it called U.S. and Israeli breaches of the memorandum's commitments, while a senior adviser to Iran's Supreme Leader stated publicly that energy flows through the Middle East would remain halted for as long as the memorandum existed "only on paper." U.S. Central Command, by contrast, maintained that the strait remained open and that Iran does not control it, reporting that vessel traffic had in fact increased through the day.
This contradiction between Iranian and American characterizations of the strait's status is itself analytically significant. It indicates that physical control of the waterway has become less determinative than the parties' competing narratives about who is honoring the ceasefire — narratives each side is using instrumentally ahead of nuclear and final-status talks that were scheduled to begin in Switzerland on June 21. Iranian state-aligned media explicitly urged Tehran's negotiating team, led by Foreign Minister Abbas Araghchi, not to arrive at those talks "empty-handed," framing the strait closure as deliberate leverage rather than a security response alone. The structural lesson for G20 policymakers is that the strait's reopening was never a single discrete event but the first move in an iterated negotiating game that is likely to feature repeated cycles of partial opening and renewed closure through the remainder of the sixty-day window and potentially well beyond it.
I.iii. Lebanon and the Escalation Ladder
Lebanon remains the most dangerous proximate escalation point precisely because it sits outside the formal U.S.-Iran memorandum while functioning, in practice, as the trigger for Iranian actions that affect the entire global economy. Israeli Prime Minister Benjamin Netanyahu has been explicit that Israel does not consider itself bound by the U.S.-Iran ceasefire's terms regarding Lebanon, and Israeli forces have continued operations against Hezbollah even as Washington and Tehran have sought to stabilize their bilateral relationship. The toll has been severe: more than four thousand Lebanese deaths have been recorded by the Lebanese Health Ministry since fighting began in early March, alongside thirty-six Israeli military fatalities in southern Lebanon and northern Israel over the same period. Hezbollah, for its part, has continued rocket fire — more than fifty rockets were reported fired at Israeli positions overnight into June 20 alone, despite a ceasefire that had nominally taken effect the previous afternoon.
From a Bayesian perspective, this is precisely the dynamic the original assessment anticipated: governments continuously revise their beliefs about adversaries' intentions and about the durability of deterrence based on incomplete and rapidly changing information, and Lebanon supplies a steady stream of such information shocks. Each Israeli strike that produces civilian casualties functions as a costly signal that Iran can credibly interpret either as a deliberate Israeli rejection of the broader ceasefire architecture or as an uncoordinated, lower-level military decision independent of U.S.-Iran diplomacy. Because Iran cannot fully distinguish between these two interpretations, it has structured its response — closing Hormuz — to be effective under either reading: it imposes a cost on the United States regardless of whether Washington can or cannot control Israeli operations in Lebanon, thereby shifting the burden of de-escalation onto the U.S.-Israel relationship rather than onto Iran's own conduct.
I.iv. Persian Gulf States, Strategic Infrastructure, and Diversification Under Duress
Persian Gulf Cooperation Council states have continued to pursue diversification of energy export routes away from exclusive dependence on Hormuz, but the war has both validated and complicated that strategy. Saudi Arabia and the UAE shut in meaningful production during the worst months of the conflict, and the resumption of Saudi-owned tanker movements through the strait on June 18 — the first since the war began more than three months earlier — was treated by markets as a significant positive signal precisely because it had been so long delayed. At the same time, pipeline and export infrastructure that bypasses Hormuz, including routes through Saudi Arabia to the Red Sea and through Iraq toward the Mediterranean, remains exposed to a different set of risks: militia activity, proxy warfare, and the same underlying regional instability that produced the Hormuz crisis in the first place. For G20 investors and policymakers, the strategic lesson is that diversification of physical routes reduces but does not eliminate exposure to the conflict, because the conflict's economic transmission mechanism is not solely about a single chokepoint but about the broader erosion of predictability across the region's energy infrastructure as a whole.
I.v. Undersea Data Infrastructure: The Persistent Gray-Zone Frontier
The vulnerability of submarine cable networks connecting Europe, Asia, Africa, and the Middle East through the Red Sea and Persian Gulf region remains an underappreciated structural risk that has not featured prominently in public reporting on the conflict to date, but which the broader pattern of the war reinforces rather than diminishes. Global financial transactions, cloud computing operations, AI systems, military communications, and international commerce depend heavily on these data arteries. Because disruption of digital infrastructure can produce substantial economic consequences while remaining below conventional thresholds of war — much as Iran's strait closures have operated below the threshold that would trigger a full military response — this gray-zone domain should be regarded by G20 leaders as a second, latent transmission channel through which regional instability could affect the global economy with little warning, even during periods when the Hormuz situation itself appears calm.
II. Global Economic Outlook: Two Institutional Scenarios and a Hawkish Policy Pivot
II.i. The OECD's Two-Scenario Framework
The most important methodological development since the original assessment was drafted is that the OECD itself has abandoned single-point forecasting for 2026 and 2027 in favor of an explicit two-scenario framework, a structure this report adopts and extends. In its June 2026 Economic Outlook, titled Under Pressure, the OECD states plainly that the conflict in the Middle East has become the dominant force shaping the global economic outlook, and that the duration of Persian Gulf energy disruptions is the single most important determinant of the difference between a moderate slowdown and what OECD Secretary-General Mathias Cormann has called the deepest global slowdown in four decades outside of the 2008–2009 financial crisis and the COVID-19 pandemic.
Under the OECD's time-limited disruption scenario — which assumes Persian Gulf energy production and exports progressively return to pre-conflict levels beginning in the third quarter of 2026 — global growth slows from 3.4 percent in 2025 to 2.8 percent in 2026, before recovering to 3.1 percent in 2027. Within that baseline, the United States is projected to grow 2.0 percent in 2026 and 1.8 percent in 2027; the euro area only 0.8 percent in 2026, picking up to 1.2 percent in 2027; China moderating to 4.5 percent and then 4.3 percent; Canada dipping to 1.2 percent before rebounding to 1.7 percent; the United Kingdom rising from 0.9 to 1.1 percent; and Japan falling to just 0.6 percent in 2026, reflecting its particular exposure to Persian Gulf energy supplies despite substantial strategic reserves. G20 headline inflation under this baseline is projected at 4.0 percent in 2026, easing to 3.1 percent in 2027.
Under the OECD's prolonged disruption scenario — in which supply constraints persist into the latter half of 2027 — global growth falls to just 2.1 percent in 2026 and 1.8 percent in 2027, a trajectory the OECD says would push several economies into or close to recession and meaningfully raise unemployment. OECD-wide growth in this scenario falls to 0.9 percent in 2026 and 0.5 percent in 2027, compared with 1.5 percent and 1.7 percent under the time-limited scenario. Inflation would be pushed higher by an additional 0.4 percentage points in 2026 and a further 1.3 percentage points in 2027 relative to the baseline, a combination the OECD's chief economist, Stefano Scarpetta, has said would likely force most central banks to raise policy rates by between fifty and seventy-five basis points beyond their current settings. Scarpetta has also noted that the impact would fall most heavily on energy-importing Asian economies and on developing economies with limited fiscal capacity, weak social safety nets, and more fragile currencies — while identifying continued artificial-intelligence-related investment, concentrated heavily in the United States, as the principal offsetting source of upside momentum in an otherwise deteriorating global outlook.
OECD Secretary-General Mathias Cormann has stated that the global economy entered 2026 with robust momentum, but that the outlook has weakened significantly since the conflict began, with effects likely to be felt for some time regardless of how or when the war itself concludes.
Both OECD scenarios occur against a backdrop the institution describes as otherwise solid underlying momentum, supported by strong artificial-intelligence-related investment, production, and trade, alongside lower effective tariff barriers than had prevailed earlier in the decade. This matters for the Bayesian framework developed in Section III: the conflict is best understood not as the sole driver of the 2026 outlook but as a large, partially reversible shock superimposed on an economy that retains genuine structural strength, particularly in technology-intensive sectors. That structural strength is precisely what allows the range between the OECD's two named scenarios to remain as wide as it is — markets and policymakers are not pricing a uniform deceleration but a genuinely bimodal distribution of outcomes contingent on the war's path.
II.ii. Inflation Dynamics: A Supply-Side Phenomenon with Second-Round Risk
Inflation in 2026 differs structurally from the inflation of 2021 through 2023. The earlier episode reflected a combination of pandemic-era fiscal expansion, supply-chain disruption, and loose monetary policy; the current episode is overwhelmingly a supply-side, geopolitically driven phenomenon concentrated in energy and energy-adjacent inputs such as fertilizer. The OECD's own framing is instructive: it has consistently argued that a supply-driven rise in prices need not by itself trigger a monetary policy response, provided inflation expectations remain well anchored, but that a response becomes necessary if broader price pressures intensify through second-round effects on wages and core inflation, or if growth weakens severely enough to require offsetting stimulus that monetary policy cannot easily provide. The events of the past several weeks suggest that several major central banks have judged the risk of second-round effects to be material enough to act preemptively, a judgment examined in the next subsection.
II.iii. Central Banks Move in a Hawkish Direction: The Fed Under Warsh and the ECB
Two decisions taken within a week of each other illustrate how the world's most important central banks are responding to an energy-driven inflation shock with monetary tightening rather than the gradual easing many investors had expected entering 2026.
The Federal Reserve: Kevin Warsh's First Meeting as Chair
On June 17, 2026, the Federal Open Market Committee held its benchmark federal funds rate unchanged at 3.50 to 3.75 percent in the first meeting chaired by Kevin Warsh, who was confirmed by the Senate on May 13 after being nominated by President Trump. The decision itself — a hold, following three successive twenty-five-basis-point cuts in September, October, and December of 2025, and holds in January, March, and April of 2026 — was widely anticipated. What was not fully anticipated was the magnitude of the hawkish shift embedded in the Committee's updated projections. The median dot now shows the federal funds rate ending 2026 at 3.8 percent, fully twenty-five basis points above the prior projection of 3.4 percent issued in March, with nine of eighteen policymakers now projecting at least one rate hike before year-end and six of those projecting two separate twenty-five-basis-point increases. The Committee's Summary of Economic Projections also raised its year-end PCE inflation projection sharply, to 3.6 percent from 2.7 percent in March, while trimming its real GDP growth projection to 2.2 percent from 2.4 percent.
Equally significant for G20 observers is the change in communication style. The Committee's post-meeting statement ran to just one hundred thirty words, compared with three hundred forty-one words after the April meeting, and explicitly removed prior language indicating a bias toward future rate cuts. Chair Warsh, who has been an outspoken critic of what he regards as Fed overcommunication, declined to submit his own projection to the dot plot — an unusual choice he defended by noting his skepticism of forward guidance as a policy tool — and announced the formation of five internal task forces to review the Fed's communications practices, balance sheet policy, data sources, productivity, and labor market analysis. At his press conference, Warsh stated unambiguously that the Committee would deliver price stability and reaffirmed the Fed's commitment to its two percent inflation target, even as consumer prices in May rose 4.2 percent year over year, the fastest pace since April 2023, and the personal consumption expenditures price index rose 3.8 percent over the twelve months through April.
This sequence is analytically important beyond its direct effect on U.S. borrowing costs. Citi's research has noted that incoming Fed chairs have historically used their first meeting to establish hawkish credibility with markets, and that the average sell-off in two-year Treasury yields around a new chair's first meeting is roughly six basis points, compared with about one basis point for an average FOMC meeting — a pattern Warsh's first meeting appears to have reproduced, notwithstanding President Trump's own publicly stated preference for lower rates. The result is a Federal Reserve that enters the second half of 2026 demonstrably more willing to tolerate slower growth in service of its inflation mandate than markets had priced at the start of the year, a posture that interacts directly with the Bayesian scenario analysis in Section III.
The European Central Bank: A Rate Increase, Not an Insurance Hike
The European Central Bank's Governing Council moved even more directly than the Fed. On June 11, 2026, it raised its three key policy rates by twenty-five basis points, lifting the deposit facility rate to 2.25 percent, the main refinancing rate to 2.40 percent, and the marginal lending rate to 2.65 percent, effective June 17. President Christine Lagarde was explicit that the decision was "robust across a range of scenarios" the ECB had modeled for how the war might evolve, and that it reflected the institution's judgment that the war in the Middle East is generating inflation pressures sufficient to warrant tightening despite a simultaneously weakening growth outlook — a combination one journalist at the post-meeting press conference described as resembling the trade-offs of the 1970s, a characterization Lagarde pushed back on directly, noting that projected growth of 0.8, 1.2, and 1.4 percent for 2026 through 2028 did not, in her assessment, constitute stagnation or recession.
The ECB's updated staff projections, prepared under the baseline scenario, foresee headline inflation averaging 3.0 percent in 2026, easing to 2.3 percent in 2027 and 2.0 percent in 2028 — each figure revised upward from the institution's March projections, reflecting a higher assumed path for energy prices that is expected to feed through into food, goods, and services inflation via indirect and second-round effects. Core inflation, excluding energy and food, is projected at 2.5 percent in both 2026 and 2027. The euro area growth projection of 0.8 percent for 2026 represents a meaningful downward revision from the institution's earlier baseline, which Lagarde attributed directly to "a more pronounced impact of the war on commodity markets, real incomes and confidence." Crucially, Lagarde declined to characterize the June decision as merely a precautionary "insurance hike," leaving open the possibility that it marks the beginning of a renewed tightening cycle rather than an isolated adjustment — a question that will not be resolved until subsequent meetings provide further data on whether energy-driven inflation is beginning to broaden into core prices and wages.
II.iv. Interest Rate Policy as a Shared G20 Dilemma
Considered together, the Fed's hawkish hold and the ECB's actual rate increase indicate that the world's two most influential central banks have reached a broadly similar judgment: that an energy-driven inflation shock currently warrants tighter, not looser, monetary policy, even though the same shock is simultaneously weakening the growth outlook each institution is separately mandated to support. This is the textbook definition of a central-bank dilemma, and it is one shared in some form by the Bank of Japan, the Bank of England, and most large emerging-market central banks through the remainder of 2026. If policy rates remain elevated, investment slows, debt-service burdens rise, and growth weakens further; if rates are reduced prematurely against a backdrop of an active, unresolved energy shock, inflation expectations risk becoming unanchored in a way that would require even larger and more disruptive tightening later. The OECD's own policy guidance — that fiscal support for households and businesses should be targeted, temporary, and structured to preserve incentives for energy conservation, with monetary policy held in reserve unless growth weakens substantially or price pressures broaden — reflects this same underlying logic, and provides the policy baseline against which the regional projections in Section III should be read.
III. A Bayesian Game-Theoretic Scenario Forecast
III.i. Methodological Note: Belief Updating Without Formal Notation
This section forecasts growth, policy interest rates, and crude oil prices across six regions under three scenarios, using a Bayesian game-theoretic logic expressed entirely in analytical language rather than mathematical notation, in keeping with the requirement that all material in this report be presented as discursive text rather than as tables or formulas. The underlying reasoning, however, follows a precise structure that is worth making explicit before turning to the regional findings.
Each actor relevant to this analysis — the government of Iran, the government of Israel, the Trump administration, European policymakers, OPEC+ producers, and financial market participants collectively — holds a prior belief about the likely path of the conflict and about the other actors' intentions. As new information arrives, such as the renewed closure of Hormuz on June 20, each actor updates that prior belief in proportion to how surprising the new information is given what was previously believed, and in proportion to how reliable or credible the source of that information is judged to be. A government that already expected intermittent disruptions updates its beliefs only modestly when another disruption occurs; a government that had genuinely believed the war was ending updates much more sharply. This is precisely why Brent crude's relatively muted reaction to the June 20 closure — a renewed disruption that left prices still far below their first-quarter peak — is itself informative: it indicates that markets had already assigned substantial probability to exactly this kind of recurrence, and were not meaningfully surprised by it.
Layered onto this belief-updating process is a strategic, game-theoretic dimension: each actor's optimal action depends on what it expects other actors to do, and each actor knows that other actors are reasoning in the same way about it. Iran's decision to close the strait is not simply a security response but a calculated signal aimed at shaping U.S. and Israeli behavior ahead of the June 21 talks in Switzerland; the United States' insistence that the strait remains open and that Iran does not control it is itself a counter-signal aimed at denying Iran the negotiating leverage that an acknowledged closure would confer. Both statements can be simultaneously true in a narrow factual sense — some vessels may continue transiting even as Iran claims the strait closed — precisely because the dispute is as much about controlling the narrative that shapes future beliefs as it is about the immediate physical movement of tankers. The three scenarios that follow represent three different long-run equilibria of this repeated, iterated game, distinguished primarily by whether the costs of continued brinkmanship eventually exceed the benefits each side derives from it, for both Tehran and Washington and Jerusalem.
III.ii. Scenario Alpha: Managed Instability (Estimated Probability: Approximately 55 Percent)
This scenario, which corresponds closely to the OECD's time-limited disruption baseline, remains the most probable path and is consistent with the pattern actually observed over the past several days: intermittent strait closures followed by renewed openings, recurring but contained proxy attacks in Lebanon and Iraq, and a negotiating process in Switzerland that repeatedly stalls and resumes without either fully collapsing or fully concluding. In game-theoretic terms, this is the equilibrium in which all major actors have concluded that the costs of full-scale renewed war exceed the benefits of continued limited coercion, but none has yet concluded that the benefits of full cooperation exceed the value of retaining leverage. Iran retains the strait as a renewable bargaining chip rather than surrendering it permanently; the United States and Israel retain the option of further strikes without escalating to a campaign aimed at regime change or total disarmament; and energy markets price a persistent risk premium rather than either a war premium or a peace dividend.
United States
Growth in the United States under this scenario tracks the OECD's baseline closely, in the range of 1.8 to 2.2 percent for 2026, consistent with both the OECD's 2.0 percent projection and the Federal Reserve's own June projection of 2.2 percent year-end growth. The labor market should remain resilient, supported by continued artificial-intelligence-related capital expenditure, but consumer spending growth moderates as energy and gasoline prices remain volatile and headline inflation stays elevated relative to target. On interest rates, the Federal Reserve's own June projections are the most credible Bayesian anchor available: a federal funds rate ending 2026 near 3.75 to 4.00 percent is more likely than not, reflecting the median dot of 3.8 percent and the real possibility, assigned by half the Committee, of one or more additional hikes should energy-driven inflation fail to recede toward target by the autumn. Crude oil under this scenario should fluctuate broadly in an eighty to one-hundred-dollar-per-barrel range for Brent, consistent both with Goldman Sachs's recently revised fourth-quarter forecast of eighty dollars per barrel and with the elevated volatility implied by a strait that continues to open and close intermittently rather than settling into either a fully open or fully closed state.
Europe (Euro Area)
European growth in this scenario should track close to the ECB's own June baseline of 0.8 percent for 2026, rising toward 1.2 to 1.4 percent in 2027 as energy markets gradually stabilize, though risks remain skewed to the downside given Europe's particular sensitivity to energy import costs relative to the United States. On interest rates, the ECB's June 11 increase to a 2.25 percent deposit rate should be read as more likely than not to represent at least one further small increase later in 2026 if energy prices remain elevated through the summer, given Lagarde's explicit refusal to characterize the move as a one-off insurance hike; a plausible range for the deposit rate by year-end is 2.25 to 2.75 percent. European crude oil exposure operates primarily through the Brent benchmark and shipping-cost channels via the Suez and Red Sea corridors as well as Hormuz, meaning European inflation remains particularly sensitive to any disruption that affects both chokepoints simultaneously, a correlated risk this report flags for particular attention by European finance ministries.
East Asia
China's growth should remain comparatively resilient in the four point three to four point eight percent range, consistent with the OECD's 4.5 percent baseline projection, supported by substantial strategic energy reserves, diversified import routes including overland pipelines from Russia and Central Asia, and continued strength in semiconductor and technology-related exports that contributed meaningfully to first-quarter 2026 growth in China, Korea, and Japan alike. Japan is more exposed under this scenario, with growth likely in the 0.5 to 1.0 percent range, consistent with the OECD's 0.6 percent baseline figure, reflecting Tokyo's heavier reliance on Persian Gulf energy imports even though its substantial strategic reserves provide a buffer against the most acute price spikes. South Korea and Taiwan should perform similarly to Japan, cushioned by resilient technology export demand but exposed on the energy-import side. None of the major East Asian economies are expected to undertake major policy rate changes under this scenario; the Bank of Japan in particular is likely to maintain a cautious, data-dependent stance given Japan's own delicate balance between import-driven inflation and continued fragility in domestic demand.
Middle East and North Africa
{ersian Gulf hydrocarbon exporters benefit, somewhat paradoxically, from elevated energy revenues even amid continued security disruption, with Saudi Arabia in particular expected to sustain growth above three percent according to IMF assessments discussed at the Fund's spring meetings, reflecting both elevated prices on the barrels it is able to export and a gradual resumption of production previously shut in in self-protection during the worst months of the war. Qatar and Iraq face more severe downgrades given their direct exposure to the conflict's physical disruption of LNG and pipeline infrastructure respectively. For the region as a whole, this scenario implies continued elevated but volatile crude oil revenue, persistent insurance and shipping cost premiums that erode some of that revenue benefit, and a policy environment in which Persian Gulf sovereign wealth funds continue large-scale international investment even as domestic fiscal planning incorporates substantial uncertainty about the durability of any given month's export volumes.
Latin America
Latin America experiences this scenario primarily as a terms-of-trade and financial-conditions story rather than a direct security exposure. Energy-exporting economies, including Brazil's offshore production and Mexico's state oil sector, benefit modestly from elevated global crude prices, while energy-importing economies face higher import bills that weigh on growth and add to domestic inflation pressures already complicated by the region's historically higher sensitivity to U.S. dollar interest rates. Regional growth in the moderate range of 2.0 to 2.5 percent appears consistent with continued commodity export support broadly offsetting tighter global financial conditions transmitted through a Federal Reserve that, as described above, is now more likely to hold or raise rates than to cut them, a dynamic that historically has tightened financial conditions across Latin American economies with significant dollar-denominated debt.
Sub-Saharan Africa
The IMF's regional analysis for Sub-Saharan Africa, presented at the Fund's spring 2026 meetings, provides the most directly applicable institutional anchor for this region. IMF staff have described 2025 as a relatively strong year for the region, supported by resilient global growth, strong non-oil commodity prices, and supportive external financial conditions, but project a cumulative growth downgrade of 0.4 percentage points across 2026 and 2027 as a direct consequence of the war, alongside a rise in median regional inflation from 3.4 percent in 2025 to 5.0 percent in 2026, driven by elevated oil and fertilizer prices and, in some cases, fuel shortages. Nigeria's growth has been revised down by 0.3 percentage points to 4.1 percent in 2026, reflecting a balance between higher fuel, fertilizer, and shipping costs weighing on non-oil activity and elevated oil prices supporting the country's hydrocarbon export earnings. The IMF has also identified a compounding headwind specific to this scenario and region: declining bilateral foreign aid, with cuts in the range of sixteen to twenty-eight percent recorded in 2025 and expected to continue, which reduces the fiscal space available to many Sub-Saharan governments to cushion their populations against the food and fuel price shock even as that shock intensifies.
III.iii. Scenario Beta: Retaliatory Cascade (Estimated Probability: Approximately 25 Percent)
This scenario corresponds to the OECD's prolonged disruption case and would emerge from a genuine strategic miscalculation rather than from the kind of bounded, repeated brinkmanship described in Scenario Alpha — for instance, an Israeli strike in Lebanon producing casualties on a scale that forces Iran's leadership to conclude that further restraint is no longer politically survivable domestically, or an attack on a U.S. naval vessel that the Trump administration judges requires a major military response rather than a negotiating signal. In Bayesian terms, this is the scenario in which one or more actors receives information sufficiently surprising relative to their prior beliefs that they discard the existing equilibrium altogether rather than making a marginal adjustment to it. Given that thirty-six Israeli soldiers and more than four thousand Lebanese have already died in the Lebanon theater alone, and that the IRGC has explicitly warned of "further measures" should Israeli operations continue, the tail risk of exactly this kind of discontinuous escalation cannot be dismissed, even though it remains the less probable of the three paths considered here.
Under this scenario, Hormuz disruptions intensify and become more sustained rather than intermittent, shipping insurance premiums surge as they did during the worst weeks of the first quarter, and financial markets move decisively into risk-off positioning. The OECD's own prolonged disruption figures provide the most credible anchor for the macroeconomic consequences: global growth falling to 2.1 percent in 2026 and 1.8 percent in 2027, with the United States approaching stagnation in the 0.5 to 1.0 percent range, the euro area falling into outright recessionary conditions of negative to roughly flat growth, and China's growth falling more sharply than under Scenario Alpha, into the 3.5 to 4.0 percent range, primarily through weaker trade and substantially higher energy import costs. Energy-importing Asian economies, and Japan in particular, would suffer the most acute pressure among major economies, consistent with the OECD's specific warning that Asian economies are disproportionately exposed in this scenario given their reliance on Persian Gulf energy supplies.
Crude oil under this scenario could plausibly retrace toward or beyond its first-quarter 2026 peak of roughly one hundred eighteen dollars per barrel for Brent, with a meaningful probability of spiking into the one-hundred-twenty-to-one-hundred-fifty-dollar range if disruptions become both broader in geographic scope and longer in duration than the worst weeks already experienced this year. Inflation would accelerate globally under this path, and the combination of weakening growth with rising prices would confront central banks with a genuinely stagflationary dilemma; the OECD itself has estimated that energy-driven price pressures in this scenario would likely force most central banks to raise policy rates by an additional fifty to seventy-five basis points beyond their current settings, even as growth deteriorates — precisely the kind of trade-off both the Federal Reserve and the European Central Bank have already begun signaling they are prepared to accept in their more modest June 2026 actions. For Latin America and Sub-Saharan Africa, this scenario implies a more severe version of the financial-stress dynamics already visible in Scenario Alpha, with several highly indebted emerging economies in both regions facing acute pressure as dollar funding costs rise in tandem with import bills, a combination that historically has preceded sovereign debt crises in both regions.
III.iv. Scenario Gamma: Structured De-escalation (Estimated Probability: Approximately 20 Percent)
This scenario represents the upside case in which the June 17 memorandum, despite its rocky first week, ultimately holds: the Switzerland talks scheduled for June 21 produce sufficient progress that Iran judges further coercive use of the strait counterproductive to its own economic interests, a sustainable Israel-Hezbollah ceasefire in Lebanon removes the principal trigger for renewed Iranian retaliation, and the sixty-day window established by the memorandum is used to negotiate durable final terms rather than simply to manage an extended stalemate. In game-theoretic terms, this is the equilibrium in which both sides conclude that the costs of continued brinkmanship — to Iran in the form of forgone oil revenue and continued economic isolation, and to the United States and Israel in the form of sustained regional instability and global economic costs that a U.S. administration facing November midterm elections has clear incentive to avoid — now exceed the benefits each derives from retaining unilateral leverage.
Under this scenario, maritime traffic normalizes more fully and durably than the brief three-day window observed between June 17 and June 20, mine-clearance operations are completed within the weeks industry analysts have estimated, and proxy activity in Lebanon and Iraq declines as Hezbollah and allied militias reduce operational tempo in response to a genuine de-escalation rather than a tactical pause. Global growth under this path would likely exceed the OECD's time-limited disruption baseline, potentially approaching the 2.9 to 3.0 percent range the OECD itself projected in its earlier March interim outlook before the worst of the conflict's economic effects had fully materialized. The United States would likely sustain growth above 2.2 percent, the euro area could recover toward 1.3 to 1.5 percent, and China would benefit from improved external demand and lower input costs across its manufacturing base.
Crude oil under this scenario should stabilize in a lower range, plausibly between sixty-five and eighty dollars per barrel for Brent, consistent with Goldman Sachs's own recently revised fourth-quarter forecast of eighty dollars and the firm's expectation that Persian Gulf crude exports return to pre-war levels by the end of July — a full month earlier than Goldman had previously projected, itself a signal that informed market participants are assigning meaningful weight to exactly this more optimistic path. Central banks would gain considerably greater flexibility under this scenario: the Federal Reserve's currently hawkish dot plot would likely be revised back toward the cuts the Committee had projected as recently as March, and the European Central Bank could plausibly pause or even begin reversing its June rate increase by early 2027 as energy-driven inflation pressures recede. For Sub-Saharan Africa and Latin America, this scenario would represent meaningful relief on both the fiscal and current-account sides, particularly given the IMF's identification of fertilizer prices and food insecurity as especially acute regional vulnerabilities that a sustained de-escalation would directly ease.
IV. Strategic Conclusions for G20 Leaders
The defining challenge confronting the G20 in the second half of 2026 is not a single geopolitical crisis but the close interaction of security competition, energy vulnerability, technological rivalry, and economic fragmentation, all operating simultaneously and reinforcing one another. The events of the past several days — a ceasefire signed with considerable diplomatic effort at Versailles on June 17, followed within seventy-two hours by a renewed closure of the Strait of Hormuz on June 20 — should be read by G20 leaders not as evidence that diplomacy has failed, but as direct empirical confirmation of this report's central analytical claim: the region has entered a durable condition of managed instability in which control over critical chokepoints functions as a renewable, low-cost instrument of coercive bargaining, deployable by Iran independent of its degraded conventional military capacity, and likely to recur repeatedly through the remainder of the sixty-day negotiating window established by the memorandum and quite possibly beyond it.
IV.i. The Strait of Hormuz Remains the Single Most Important Near-Term Risk to the Global Economy
Even partial or temporary disruptions to Hormuz traffic generate economic effects disproportionate to their physical duration, because shipping insurers, financial markets, and downstream industrial users price the probability of renewed closure rather than waiting to observe it directly. The fact that Brent crude retraced roughly the entirety of its first-quarter gains even before the June 20 closure, and then absorbed that closure with only a modest reaction, demonstrates that markets are now pricing a probability distribution over outcomes rather than reacting to each individual headline as a discrete shock. This is, in one sense, a sign of market maturity and adaptive resilience. It also means, less reassuringly, that the underlying risk premium embedded in energy prices, shipping insurance, and broader financial conditions is likely to remain structurally elevated for as long as the conflict's resolution remains genuinely uncertain — which, on the evidence of the past week, is likely to be measured in months rather than days.
IV.ii. Economic Resilience Increasingly Depends on Infrastructure Security Broadly Defined
Global economic resilience in this environment depends not only on the physical security of energy infrastructure and shipping routes, but increasingly on the security of satellite networks and undersea communications cables that carry the financial, logistical, and AI-related data flows on which modern economic activity depends. These assets have become, in effect, central components of national and collective economic security, even though they remain largely outside the formal mandates of most G20 finance ministries and central banks. The G20's institutional architecture for monitoring and responding to economic risk was built primarily around financial and macroeconomic indicators; the events of 2026 suggest that architecture needs to be extended to incorporate physical and digital infrastructure risk as a first-order macroeconomic variable rather than a peripheral security concern.
IV.iii. The Most Probable Future Is Neither Comprehensive Peace Nor Renewed Major War
Based on the Bayesian scenario analysis developed in Section III, the most probable trajectory for the remainder of 2026 is neither a durable comprehensive peace nor a return to the full-scale hostilities of February through May, but a prolonged period of managed instability characterized by recurring shocks, elevated volatility, and a persistent geopolitical risk premium embedded across energy, shipping, insurance, defense, and financial markets. This finding should reshape how G20 finance ministries approach near-term fiscal and monetary planning: scenario-contingent rather than single-point forecasting, of the kind the OECD itself has now adopted, should become the standard methodology for G20 economic surveillance for as long as this condition persists, rather than a temporary departure from normal practice.
IV.iv. Recommendations
Maintain and, where necessary, expand strategic petroleum reserves and coordinated release mechanisms among G20 energy-importing economies, calibrated to the intermittent rather than continuous nature of the Hormuz disruption pattern observed to date.
Ensure that any fiscal support extended to households and businesses to cushion energy price volatility remains targeted, temporary, and structured to preserve incentives for energy conservation, consistent with the OECD's explicit policy guidance, in order to protect medium-term fiscal sustainability across G20 economies already carrying elevated public debt.
Treat central bank communication and policy calibration as a coordination problem rather than a purely domestic one: the near-simultaneous hawkish pivots by the Federal Reserve and the European Central Bank illustrate how a shared external shock can produce correlated tightening across major currency areas, with compounding effects on global financial conditions that are larger than the sum of each individual decision.
Extend G20 economic risk-monitoring frameworks to explicitly incorporate undersea cable and satellite infrastructure security alongside traditional energy and shipping route risk, given the latent but largely unaddressed exposure of global financial and AI-related data infrastructure to the same regional instability driving the energy shock.
Provide targeted multilateral support, through the IMF, World Bank, and bilateral channels, to the most exposed Sub-Saharan African and Latin American economies identified in this report, particularly given the compounding effect of declining bilateral foreign aid on top of elevated fuel and fertilizer costs in Sub-Saharan Africa specifically.
Support continued, well-resourced mediation efforts, including the Pakistani, Qatari, and Swiss channels currently in use, while recognizing that durable de-escalation likely requires parallel progress on the Lebanon track, given that Israeli-Hezbollah dynamics haverepeatedly functioned as the proximate trigger for renewed Hormuz disruptions even though Lebanon sits formally outside the U.S.-Iran memorandum itself.
For the G20, the central policy challenge of the second half of 2026 is therefore not crisis resolution alone, but the construction of institutions and decision-making frameworks capable of sustaining economic stability amid a form of geopolitical uncertainty that may not resolve cleanly for a considerable period. Resilience — understood as the capacity to absorb recurring, partially reversible shocks without systemic disruption — rather than optimism about any single negotiating breakthrough, should be regarded as the defining strategic requirement facing G20 economic policymakers through the remainder of the decade.
Sources
This report draws on verified reporting and institutional publications current as of June 20, 2026, including: the OECD Economic Outlook, Volume 2026, Issue 1 ("Under Pressure") and accompanying press materials; the European Central Bank's June 11, 2026 monetary policy decision and press conference transcript; the U.S. Federal Reserve's June 17, 2026 FOMC statement, Summary of Economic Projections, and chair press conference; the International Monetary Fund's April 2026 World Economic Outlook, Spring 2026 press briefing transcript, and Sub-Saharan Africa Regional Economic Outlook; the U.S. Energy Information Administration's first-quarter 2026 petroleum markets review; and contemporaneous reporting from Reuters, the Associated Press, CNN, NBC News, Bloomberg, CNBC, NPR, the Washington Times, Fox Business, and CBS News on the status of the Strait of Hormuz, the June 17 U.S.-Iran memorandum of understanding, and developments in Lebanon through June 20, 2026.
This report is preliminary and prepared for internal review. Given the exceptional fluidity of the underlying situation — illustrated by the reopening and renewed closure of the Strait of Hormuz within a single week — all scenario probabilities and regional projections should be understood as point-in-time assessments subject to revision as the situation evolves, including in particular the outcome of talks scheduled to begin in Switzerland on June 21, 2026.
