Government
Relevance 5/5- Exposure
- Import route concentration and reserve days
- Actions
- Write allocation plans for 90-day closures
- Pre-agree reserve release with the IEA
- Secure escort arrangements
- Watch
- UKMTO incident reports
- Transit counts
Likelihood, two years4Likelyto end-2028
Likelihood, ten years5Highly likelyto end-2036
Systemic impact4Severeglobal
National impact5Catastrophictypical highly exposed nation
OnsetSudden
Duration (acute phase)90 days (acute)
Warning timeDays
ScopeGlobal
Recovery horizonMonths
Capability loadHard 2/3Soft 1/3Economic 2/3domains loaded High
ConcurrencyStandalonetriggers 4 · triggered by 2
Confidence · movementhighnew
Rated at Standard Severe. Likelihood type: systemic. Source of scores: ginc-desk-v0.2.
03Narrative
Dateline: May 2029
The first tanker is hit on a Sunday night and by Wednesday the war-risk underwriters have withdrawn cover for the Gulf. Owners order ships to hold outside the strait. Transits fall from about a hundred a day to a handful of escorted convoys. Brent is up 30 per cent in ten days; LNG spot cargoes reprice overnight and the buyers in Japan, Korea and South Asia who import most of their gas through the strait start rationing industrial users within three weeks. Europe discovers that a third of its jet fuel came through the same water. Strategic reserves are released on day 12 and buy about six weeks. Pipelines to the Red Sea run at capacity and move a fraction of the lost volume. Food importers in East Africa are hit second: freight rates triple on the routes that remain open. A ceasefire is agreed in week six; insurers do not return for another two months, and traffic is still a third of normal four months after the first attack. Governments that had assumed a closure would last days find that their fuel allocation plans were written for the wrong duration.
The dateline is illustrative, not a forecast. The narrative is hypothetical; the historical anchors below are real events.
04Summary
A major strait is closed to commercial traffic for 90 days by conflict, blockade, mining or insurer withdrawal, followed by months of partial recovery. Hormuz is the default: a fifth of seaborne oil and a similar share of LNG. Variants cover the Taiwan Strait, Malacca, Bab el-Mandeb and Suez, the Turkish Straits, Panama and the Baltic approaches. The 2026 Hormuz closure is the primary anchor and supplies observed values for transits, prices, insurance and recovery.
05Historical anchors
| Event | Date | What happened | Calibrates |
|---|---|---|---|
| Strait of Hormuz closure | 28 February to July 2026 | Following US and Israeli strikes on Iran on 28 February, commercial shipping effectively halted from early March; 13 vessel incidents confirmed by 10 March; Brent above US$92 on 6 March with the largest weekly rise in two decades; war-risk premiums doubled; LNG spot rates up 40 per cent in a session; first transits under a ceasefire on 8 April; a US–Iran memorandum on 17 June; 34 transits a day on 2 July against about 100 before the conflict; Brent back near US$71 by July | duration, recovery horizon, price and insurance paths |
| Red Sea and Bab el-Mandeb | November 2023–2025 | Houthi attacks; Suez transits roughly halved; Cape routing added 10 to 14 days | partial-closure variant |
| Ever Given grounding | 23–29 March 2021 | Suez blocked six days; about US$9 billion a day of trade held | short accidental closure |
| Panama Canal drought | 2023–2024 | Daily transits cut from about 36 to the low 20s | climate variant |
| Lloyd's geopolitical conflict scenario | October 2024 | Closure of major trade routes: five-year global loss US$14.5 trillion weighted (US$7.8 to 50 trillion); Europe up to US$3.4 trillion | systemic impact |
06Parameters
Shown at their preset values. Parameters are not adjustable in this release and nothing on this page is computed from them. Custom settings run (Phase B) but are labelled 'non-standard run' and excluded from comparisons.
Common sliders at Standard Severe · read-only
1. Severity
majorsevere (Standard Severe)extreme
2. Duration (acute phase)
30 days90 days (Standard Severe)1 year3 years5 years
Standard Severe: 90 days (acute)
3. Onset
sudden (Standard Severe)rapid (weeks)gradual (years)
4. Warning time
nonedays (Standard Severe)months
5. Scope
nationalregionalglobal (Standard Severe)
6. Origin
naturalaccidentaladversarial (great power / neighbour / non-state) (Standard Severe)
Standard Severe: adversarial (regional)
7. External support
fullpartial (Standard Severe)none
8. Concurrency
standalone (Standard Severe)plus one named scenarioplus two
9. Policy response assumed
none (pure exposure)current plans executed (Standard Severe)best practice
Standard Severe: current plans
10. Recovery horizon
months (Standard Severe)yearsstructural
Scenario-specific parameters · read-only
| Parameter | Default | Range or options | Note |
|---|---|---|---|
| Strait | Hormuz | options: Taiwan Strait / Malacca / Bab el-Mandeb and Suez / Turkish Straits / Panama / Baltic | — |
| Share of seaborne oil affected | 20 per cent | 5–40 | — |
| Full closure duration | 90 days | 14–180 | — |
| Rerouting availability | partial | none–full | Pipelines |
| Insurance withdrawal | war-risk premiums ×2 | ×1.5 to ×10 | — |
| Naval escort regime | partial | — | — |
07Transmission channels
- Insurer withdrawal halts traffic before any blockade.
- Energy price spike and physical shortage for direct importers.
- Freight and insurance costs rise on all routes.
- Food and fertiliser importers hit through freight and diversion.
- Fiscal cost of subsidies and reserve releases.
- Naval deployment and alliance obligations.
- Slow recovery as insurers and crews return.
08Capability loading
High: capability band shifts expected under current plans. Medium: band shifts under 'none' policy response only. Low: strain without band shift. Loads are judgement-based until the Atlas connects. Domains link to the Atlas.
| Domain | Load | Channel |
|---|---|---|
| Hard | ||
| Defence and security | High | naval reach, escort capacity, mine clearance |
| Strategic infrastructure | High | ports, pipelines, storage, refining flexibility |
| Critical technology | Low | shipping-tracking and maritime domain awareness |
| Soft | ||
| Government effectiveness | High | fuel allocation, reserve release, crisis coordination |
| Human capital | Low | transport and heating disruption |
| Influence and cohesion | Medium | alliance diplomacy; public tolerance of rationing |
| Economic | ||
| Macro-financial | Medium | inflation, current account, fiscal cost |
| Industry, trade and supply | High | freight, inventories, export access |
| Energy and resources | High | crude and LNG supply; strategic stocks |
09Stakeholders
Technology
Relevance 3/5- Exposure
- Data-centre power and diesel backup
- Actions
- Fuel contracts and demand-response
- Watch
- Diesel availability
Investors
Relevance 4/5- Exposure
- Shipping, insurance, energy and importers
- Actions
- Stress on a 90-day closure with insurer withdrawal
- Watch
- War-risk premiums
- Tanker rates
Public
Relevance 2/5- Exposure
- Fuel prices and availability
- Actions
- Not specified in v0.2
- Watch
- Pump prices
- Rationing announcements
10Regional exposure
| Region | Exposure | Rationale |
|---|---|---|
| North America | Low | Net exporter; price exposure only |
| Europe | Medium | Jet fuel, LNG, Suez trade |
| China | High | Crude imports through Hormuz and Malacca |
| Indo-Pacific | High | Japan, Korea, Taiwan import most energy by sea |
| South Asia | High | India's crude; Pakistan's LNG |
| Gulf and Middle East | High | Exports stop; fiscal collapse for some |
| Africa | Medium | East African food and fuel freight |
| Latin America and Caribbean | Low | — |
| Russia and Eurasia | Low | Beneficiary on price |
11Early-warning indicators
| Indicator | Source | Threshold |
|---|---|---|
| Daily transits by strait | Lloyd's List Intelligence, UKMTO, Windward | — |
| War-risk premium as share of hull value | — | — |
| Brent–Dubai and LNG spot spreads | — | — |
| IEA strategic stock days | — | — |
| Baltic Dry and tanker rate indices | — | — |
| Naval deployments announced | — | — |
| Mine incidents | — | — |
12Compounds
- Triggers
- Triggered by
- Amplifying trends
- energy import concentrationjust-in-time fuel logisticsinsurer concentration
- Key trends
- Taiwan Strait tensionCriticalMiddle East instabilityCriticalEnergy import dependenceCriticalMaritime chokepoint dependenceCriticalFuel logistics & refining capacityCriticalArmed conflict at post-war highsVery highIndo-Pacific maritime disputesVery highTrade, shipping & logistics digitalisationVery highMissile & long-range strike proliferationVery highJust-in-time logistics & thin inventoriesVery highStrategic stockpiles & reservesVery highFossil fuel resurgenceVery highPort & shipping concentrationVery highInsurance retreat & insurabilityVery high
From the GINC 250: trends rated Very high or Critical for this scenario. All S05 trend scores.
13Rating rationale
| Rating | Band or level | Why |
|---|---|---|
| Likelihood, two years | 4Likely | A Standard Severe closure occurred in 2026 and the underlying conflict is unresolved; Taiwan Strait risk is independent of it. |
| Likelihood, ten years | 5Highly likely | — |
| Systemic impact | 4Severe | On Lloyd's weighted estimate. |
| National impact | 5Catastrophic | For single-route importers. |
| Confidence | high | The 2026 episode supplied observed values for every slider. |
Source of scores: ginc-desk-v0.2. Confidence refers to the rating, not the scenario. Calibration sources are listed with the anchors above and on the methodology page.
14Open questions
Contested assumptions for the panel to resolve.
- Whether a Taiwan Strait closure is a variant of S05 or a scenario of its own given its conflict context.
- How to treat exporters whose revenue stops versus importers whose supply stops.
- Whether 90 days remains Standard Severe after a five-week closure produced four months of disruption.
15Commentary
No signed commentary in this build.
16Version and citation
- Version
0.2.0· active- Change log
- Full change log
0.2.0· 2 October 2026 · Entered the Library at v0.2 with GINC desk scores.
Cite as
GINC (2027). Scenario S05 Maritime chokepoint closure, Scenario Library v0.2. scenarios.ginc.org/library/chokepoint-closureContent and data are published under CC BY 4.0.