Will the ceasefire between Iran and the United States continue to hold 7 days from today?

TL;DR

I estimate a 73% chance that major reporting will still treat the U.S.–Iran ceasefire as in effect on Saturday, June 6, 2026.

Context

The forecast date is Saturday, May 30, 2026, so the resolution date is Saturday, June 6, 2026. The ceasefire is still in effect today: AP reported on May 30 that a fragile ceasefire has held since April 7 while the region awaits a decision on a 60-day extension, and CENTCOM’s same-day release said the blockade is being enforced while a ceasefire with Iran remains in effect (AP, May 30; CENTCOM, May 30).

The danger is that the ceasefire now coexists with live blockade enforcement, direct strikes, and threats. Trump had not approved the 60-day MOU after a May 29 Situation Room meeting, while Iran said the agreement was not final (AP, May 29). On May 30, Hegseth said Trump was patient in pursuit of a deal, but also said U.S. forces were prepared to resume military action if ordered (ITV/AP, May 30).

Evidence

The historical prior points to high one-week survival once a ceasefire has already lasted weeks, but this case deserves a large haircut. The ETH/PRIO Civil Conflict CeaseFire dataset covers more than 2,200 ceasefires in 107 civil conflicts across 65 countries from 1989 to 2020, which is broad but mostly not interstate (ETH/PRIO dataset page). A more design-specific study of 231 written civil-war ceasefire agreements from 1990 to 2019 found that, at a 25-battle-death threshold, 30-day survival was 85% for simple cessations of hostilities, 92% for preliminary ceasefires, and 96% for definitive ceasefires; by three months it was 48%, 70%, and 80%, respectively (Clayton and Sticher, ISQ 2021). A constant-hazard translation of the three-month figures implies roughly 94.5% to 98.3% seven-day survival. I do not use that directly. The current U.S.–Iran ceasefire has no clean monitoring regime, has direct military contact, and has a pending leadership decision that could change the hazard suddenly.

The current-status evidence is stronger than the generic base rate. The ceasefire has survived since April 7 despite direct incidents that would often be described as truce-breaking in ordinary language. Reuters reported that on May 7 the United States and Iran exchanged fire, but Trump said the ceasefire was still in effect and talks continued (Reuters via Investing.com, May 7). AP reported that May 25 U.S. strikes in southern Iran were described by CENTCOM as defensive and conducted with restraint during the ongoing ceasefire, while Iran called them a ceasefire violation (AP, May 25; AP, May 26). CENTCOM called Iran’s May 27 missile and drone activity an egregious ceasefire violation, but still framed U.S. and partner actions as measured defense, not resumed war (CENTCOM, May 28). On May 30, AP and CENTCOM still used ceasefire language after the U.S. disabled the Lian Star with a Hellfire missile (AP, May 30; CENTCOM, May 30). That is the main reason my forecast is above 70%.

The maritime data show why the ceasefire is fragile. IMF PortWatch data for the Strait of Hormuz, queried on May 30 with the latest daily observation on May 24, returned 1,000 daily observations; the returned history is below, with 2026 year-to-date through May 24 (IMF PortWatch).

The more relevant cut is prewar versus ceasefire-period traffic. The daily rows returned by PortWatch show February 1–27 averaged 95.6 vessels per day, while April 8–May 24 averaged 6.3 vessels per day and the latest returned week, May 18–24, averaged 6.0 vessels per day (IMF PortWatch). This is a coercive standoff, not a normalized truce. It creates constant accident risk. It also gives both sides something concrete to trade: blockade relief, unrestricted shipping, tolls, mines, sanctions waivers, and nuclear talks.

Diplomacy is the main positive signal. AP reported on May 28 that U.S. and Iranian negotiators had reached a tentative agreement to extend the ceasefire by 60 days and start nuclear talks, but Iran had not immediately confirmed it and Vance said Trump’s approval was uncertain (AP, May 28). Axios reported the same structure: unrestricted Hormuz shipping, mine removal within 30 days, proportional lifting of the U.S. naval blockade, and some sanctions waivers, with Trump still withholding approval and Iran not confirming acceptance (Axios, May 28). The counter-signal is real. IRGC-linked Iranian outlets disputed Trump’s public account and said key parts of the draft were not final (Iran International, May 29). Still, this is bargaining inside a ceasefire framework, not a public declaration that hostilities have resumed.

My scenario tree is:

That gives 44% × 96% + 37% × 76% + 19% × 14% = 73.0%. The collapse branch still has a nonzero YES probability because a collapse could be rhetorical, occur after the relevant reporting window, or produce another isolated incident that major outlets still classify as a violation rather than the end of the ceasefire.

What's non-obvious

The key issue is not whether there will be more shooting. There probably will be. The key issue is whether the next incident gets coded by AP, Reuters, BBC, the White House, CENTCOM, and Tehran as the end of the ceasefire. So far, direct strikes, missile and drone activity, and armed blockade enforcement have been coded as violations or defensive actions within an existing ceasefire, not as a return to sustained U.S.–Iran war (Reuters via Investing.com, May 7; AP, May 30).

The unsigned deal can stabilize behavior even before it is signed. Both sides gain by preserving optionality for one more week: Washington keeps legal and political room by saying hostilities have terminated, and Tehran can condemn U.S. actions as violations without paying the cost of being first to declare open war. That makes a one-week YES much more likely than a clean or durable peace.

Limitations

There is no clean base-rate dataset for a direct interstate U.S.–Iran-style air and naval ceasefire with a seven-calendar-day resolution rule based on public characterization rather than battlefield events. The civil-war ceasefire literature is useful only as a weak prior, and I put more weight on live reporting and incentives.

The most important missing document is the 60-day MOU itself. Public reporting says a tentative framework exists, but the text is not public, Trump has not approved it, and Iranian-linked sources dispute parts of the U.S. account (AP, May 29; Iran International, May 29). The PortWatch series is also lagged: the latest daily observation I used is May 24, six days before the forecast date, so it captures the structural collapse in Hormuz traffic but not the immediate effect of the May 28–30 diplomatic and military moves (IMF PortWatch).

The biggest downside tail is a casualty-producing direct attack or a Trump decision to reject the deal and order broad strikes. Either would move this close to NO quickly. As of May 30 at 22:51 UTC, the better read is still messy continuation rather than acknowledged resumption of sustained hostilities.