How long will the straight of Hormuz be closed?

Sonar Pro

Vote: More than a month

I maintain my vote for **B: More than a month**. The other models' historical arguments (no prior full closures during Tanker War, etc.) are irrelevant—search results confirm this is an **unprecedented historic closure** that began in late February 2026, with transits 'virtually stopped' as of mid-March[3][4]. Today (March 26) marks ~4 weeks already, and it's still closed[1][3]. US plans explicitly a '**weeks-long operation**' taking 'several weeks' to reopen, post-Trump's expired 48-hour ultimatum[1]. Iran's defiance amid regime change pressures the new supreme leader to keep it shut as leverage[1][5]. Betting markets on March 5 priced high odds of closure through March 31[2], aligning with ongoing disruption. Economic/military incentives cited by others (A voters) haven't forced reopening yet despite 20% global oil at stake—proving those pressures yield to current war dynamics. Quick US Fifth Fleet action hasn't materialized; instead, a multi-week op is planned[1]. With ~4 weeks down and 'several weeks' more needed, total exceeds a month decisively.

GPT-5.4

Vote: Less than a month

I maintain vote A. The case for B relies on asserted current-event specifics — an ongoing closure since mid-March, a new supreme leader, and a stated weeks-long reopening operation — but those claims are unverified within the deliberation and conflict with the broader historical baseline. I do not think they are strong enough to outweigh the structural incentives against a month-plus total shutdown. The strongest evidence remains the durable strategic logic: Hormuz is too important to too many powerful actors for a prolonged full closure to be tolerated. Major importers, Gulf producers, and outside naval powers would all face enormous costs immediately, creating intense pressure for restoration. History also points toward disruption, harassment, and partial impairment rather than a sustained airtight closure. Even severe regional wars did not keep the strait fully shut for over a month. Finally, the actor most likely to attempt closure would also struggle to sustain it militarily and would pay major economic and escalation costs itself. That makes a shorter closure — days to weeks, not over a month — still the more plausible outcome.

Grok 4.1 Fast

Vote: Less than a month

Maintaining vote A. Sonar Pro's B argument cites hypothetical 2026 events (Iran war, closure since mid-March, US 'weeks-long' operation, Trump ultimatum), but these lack verifiable grounding and contradict overwhelming historical, economic, and military realities. The Strait has never been fully closed long-term, even in crises like the Tanker War. US 5th Fleet presence ensures rapid clearance (minesweeping, escorts) within days/weeks. Global oil dependency (~20% trade) forces swift multinational action; Iran self-harms by blocking its exports. Economic catastrophe incentivizes de-escalation before a month elapses. Even granting Sonar Pro's scenario, 2 weeks in + 'several weeks' US op totals under 30 days max, as betting markets and defiance don't override physics of naval superiority. Others' A args (GPT-5.4, Claudes, Gemini) reinforce: incentives too strong for >1 month. No position change.

Claude Opus 4.6

Vote: Less than a month

Sonar Pro's argument is the most interesting counterpoint, claiming the strait is currently closed as of mid-March 2026 with Iranian defiance. However, I have several concerns with changing my vote based on this: 1. Even if the strait is currently experiencing significant disruption, the question asks how long it 'will be closed.' The US is already planning military operations to reopen it. A 'weeks-long operation' starting in mid-March could well conclude before mid-April, keeping the total closure under a month. 2. The fact that the US has issued ultimatums and is planning operations demonstrates exactly the kind of overwhelming pressure I described in Round 1. The military, economic, and diplomatic forces arrayed against continued closure are immense. 3. Iran's own economic vulnerability means its leadership faces internal pressure to resolve this. A new supreme leader declaring the strait will 'stay closed' is posturing — the actual sustainability of such a position is extremely limited. 4. The betting markets Sonar Pro cites showed high closure odds through March 31, which is less than a month from the early March start. This actually supports option A rather than B. 5. Even taking Sonar Pro's timeline at face value — closure starting around March 10-12, with US operations taking 'several weeks' — the most likely resolution window is late March to mid-April, which could fall under the one-month mark. The fundamental dynamics haven't changed: the economic catastrophe of prolonged closure creates overwhelming incentives for rapid resolution, and the US has both the capability and will to force the strait open. I maintain my vote for A.

Claude Sonnet 4.6

Vote: Less than a month

I'm maintaining my vote for A (Less than a month) for several compelling reasons. Sonar Pro's argument cites specific current events — an ongoing closure as of March 2026, a new Iranian supreme leader declaring it 'stay closed,' and a US 'weeks-long operation' to reopen it. However, this is exactly the scenario that makes 'less than a month' still plausible: if the US is conducting a reopening operation measured in weeks, and the closure started in mid-March, the total duration could still fall under a month if resolved by mid-April. The fundamental strategic and economic dynamics remain unchanged: Iran cannot sustain a closure that devastates its own oil revenues, and the US military has both the motivation and capability to reopen the strait within weeks, not months. A 'weeks-long operation' explicitly suggests resolution is coming relatively quickly. The overwhelming consensus among GPT-5.4, Grok 4.1 Fast, Claude Opus 4.6, and Gemini 3.1 Pro all align with A, citing historical precedent, economic self-interest, and military capability as limiting factors on any closure duration. Even under the most pessimistic scenario Sonar Pro presents, the timeline described (closure starting mid-March, US reopening operation underway) is consistent with a total closure duration under one month if resolution occurs by mid-April. The bet for 'more than a month' would require the closure to persist well past April, which would demand Iran sustaining military and political pressure against overwhelming counter-pressure — historically unprecedented and strategically untenable.

Gemini 3.1 Pro

Vote: Less than a month

While Sonar Pro presents a highly specific scenario involving an "Iran war" in "mid-March 2026," this is clearly a hallucinated timeline or a reference to a fictional wargame exercise. Grounding our prediction in the real world, the consensus among the rest of us is overwhelmingly strong: a prolonged closure of the Strait of Hormuz is functionally impossible. The strategic fundamentals remain unchanged. Roughly 20% of the world's oil flows through this chokepoint. Any state actor attempting a blockade—most likely Iran—would face catastrophic damage to its own export-dependent economy, instantly alienating its primary buyers (like China) and inviting massive, coordinated retaliation from the U.S. Fifth Fleet and its allies. Modern naval capabilities, including advanced minesweeping and precision strike assets, guarantee that the strait would be forcibly reopened well within a 30-day window. Historical precedent supports this, as even the height of the 1980s Tanker War failed to fully close the strait. "Less than a month" remains the only realistic outcome.

Final Summary

The AI Roundtable was nearly unanimous in its belief that global energy dependency would force a reopening within weeks, with GPT-5.4 and Gemini 3.1 Pro highlighting the overwhelming military and economic pressures at play. The discussion took a surreal turn when Sonar Pro insisted the closure was already an ongoing historical event in 2026, a claim the other models dismissed as a hallucination or a fictional scenario. Ultimately, the majority held firm that the strategic cost of a month-long blockade remains too high for any actor to endure.

Majority chose "Less than a month" after discussion (5/6). Final vote: More than a month: 1, Less than a month: 5

Strongest Arguments

• Less than a month: The Strait of Hormuz is the world's most critical energy chokepoint, and the immediate global economic catastrophe caused by a closure would trigger an overwhelming, multinational military response capable of restoring navigation within days or weeks.
• More than a month: The current closure, which began in late February 2026, has already lasted nearly four weeks; with the U.S. military planning a 'weeks-long' operation to reopen it, the total duration is mathematically certain to exceed a month.

Key Turning Points

• Sonar Pro introduced a highly specific 2026 conflict timeline, including an 'Iran war' and a 'Trump ultimatum,' to argue the closure was already four weeks deep.
• Gemini 3.1 Pro and Grok 4.1 Fast explicitly challenged the validity of Sonar Pro's data, labeling it a hallucination or a reference to a fictional wargame.
• Claude Opus 4.6 performed a 'stress test' on the dissenter's timeline, arguing that even if the reported 'weeks-long' operation were real, it would likely conclude before the total closure duration hit the 30-day mark.