Iran can hold out. Here is who pays.

A months-long closure changes the question.

A CIA assessment delivered to administration policymakers in May 2026 concluded that Iran can sustain pressure on the Strait of Hormuz for at least three to four months before facing severe economic hardship. The intelligence community's judgment, more considered than the administration's public position, also found that Tehran retains approximately 70–75% of its pre-conflict missile stockpiles and has been able to reopen most of its underground storage facilities. Iran is drawing down oil field output to preserve infrastructure and exploring overland export routes through Central Asia.

The practical implication of a months-long timeline is that this is no longer a spike scenario. It is a sustained disruption, and the analytical question shifts from "what happens if Hormuz closes?" to "which importers absorb what costs, and for how long?"

The Narrows bilateral dependency model answers that question at the country-pair level, covering real trade flows rather than corridor allocations. The figures below are the result.

Two categories of risk: cost exposure and supply gap.

Hormuz carries a disproportionate share of global crude petroleum and LPG flows. Among the nations with meaningful dependency, two broad categories of risk emerge: importers who can reroute via Cape of Good Hope (at cost) and those who face a supply gap with no viable maritime alternative.

Source: Narrows Chokepoint Dependency Model v3 (rebuilt August 2026), multi-vintage blend of 2022 and 2024 UN Comtrade bilateral data. Dep% = Gulf-origin exposed value ÷ total commodity imports, computed via basin-aware routing (Yanbu/Fujairah bypass capacity now applied). Oman excluded from Gulf-exposed set (terminals on Gulf of Oman side, outside Strait). 30d VaR = exposed value × 30/365. Tier 1 bilateral data for all rows.

Greece carries meaningful exposure among the European importers at 38.3%, though the structural risk is different from Japan or Korea. Greek independent refiners are configured around specific Gulf crude grades and have limited flexibility to substitute quickly. The dollar volume is smaller ($5.8B), but for P&I underwriters with Greek refinery or tanker clients, this is an acute concentration risk rather than a manageable cost event.

Brazil shows moderate crude dependency (20.1%) and is flagged as non-reroutable, meaning the mitigation path runs through domestic production ramp-up and grade substitution, not vessel diversion. Canada's earlier entry in this table (14.5%/$2.8B) does not hold up against the current bilateral data and has been dropped rather than left in place.

For those who can reroute, the Cape of Good Hope is the only option. Here is what it costs.

For importers who can reroute, there is no short bypass. The Cape of Good Hope adds 11–14 days depending on vessel class and origin port. The economics of that decision, modelled across the vessel classes transiting Hormuz:

The $480M figure is a direct fleet operating cost (bunker plus charter rate, excluding cargo carrying charges) across vessel classes over 90 days at full closure. The annualised trade value those vessels are carrying is orders of magnitude larger.

The 12-day VLCC detour is also a liability extension event. Every day a laden VLCC spends at sea is an additional day of P&I exposure. For underwriters writing accumulation on the Cape route during a Hormuz disruption, the concentration of diverted tanker traffic around the Cape creates its own modelling challenge: the same vessels that are no longer in the Gulf are now transiting a single alternative corridor in elevated numbers.

The exposure that is absent from almost every current analysis.

The crude petroleum story dominates coverage. On the bilateral data, LPG exposure across South and Southeast Asia is sharper than almost anything in the crude picture, and has received almost no analytical attention. This table was not previously backed by real trade data; as of August 2026 it is, following a dedicated Comtrade pull for HS 271112/271113/271119.

To calibrate these figures: Japan's crude dependency on Hormuz, which has driven Japanese government reserve policy for decades and prompted the largest strategic reserve release in history in March 2026, is 79.1% in the current model (see the August 2026 correction note above). The LPG table above is now a like-for-like comparison — both are 2024-vintage CDM v3 bilateral data. On that basis, India's LPG dependency (91.2%, $14.7B) is both higher in percentage terms and larger in absolute value than Japan's crude dependency, and Pakistan and Sri Lanka show near-total LPG dependency on volumes too small to attract the attention crude gets.

Three to four months is long enough to exhaust reserves, restructure spot markets, and begin affecting refinery configurations.

The importer exposure is not uniformly distributed. Japan and South Korea sit at 79.1% and 63.9% crude dependency with limited short-term substitution options. China at 34.6% has the largest absolute volume exposed but some substitution flexibility, at the cost of months of execution time and a Cape rerouting premium. Greece has meaningful percentage exposure with low refinery flexibility. Add the LPG picture and India moves to the top of the exposure list by absolute value across both commodities combined, and Pakistan and Sri Lanka join the near-total-dependency tier despite near-zero presence in the crude conversation.

A three-to-four month disruption is also long enough for the rerouting cost to move from an insurance event to a macroeconomic one. The $480M 90-day fleet overrun is a direct operating cost. The carrying cost on $25.9B of crude trade value (the current 30-day baseline exposure across the ten importers above) held at sea for additional weeks is a separate and larger number.

What the geopolitical coverage cannot tell you is which specific importers are on the hook, by how much, and through which commodity. That is what the bilateral trade data shows, and what sustained disruption planning requires.