Hormuz Crisis Tracker — 2026-05-31 · Cycle 1 (Desktop Substrate)

War Day: 93 | Ceasefire Day: 55 | Cycle: C115 (est. — terminal marker was C107 on 2026-05-28 morning per Scout Status note; desktop file series last at C88/May 16)
Grok bridge: NO — latest Grok HORMUZ X-PULSE in Apple Notes is April 29 (stale). Full web sweep run.
Baseline: C88 / 2026-05-16 Night Cycle (15-day gap — this is a catch-up cycle, deltas span the full interval)

⚡ CRITICAL FLAGS THIS CYCLE

• 🟢 TENTATIVE US–IRAN DEAL REACHED (MAY 28–29) — NOT YET SIGNED: US and Iranian negotiators reached a tentative agreement to extend the ceasefire by 60 days and open a new round of nuclear talks. MOU includes an Iranian commitment not to pursue a nuclear weapon; the first issues for the 60-day window are HEU disposal and enrichment. In exchange the US would gradually lift the naval blockade and relax sanctions, allowing Iran to sell more oil. Trump ended the May 29 Situation Room meeting without a final determination. VP Vance: tentative agreement reached Thursday evening, "hard to say exactly when or if the president's going to sign… going back and forth on a couple of language points." This is the most advanced diplomatic state of the crisis — but it is not signed and not final.
• 🟢 US NAVAL BLOCKADE OF IRAN ENDED (MAY 29): The US blockade of Iranian ports (ran April 13 → May 29) was announced ended by Trump following negotiations. However enforcement continued past the announcement: on May 30 the US said it disabled another commercial ship attempting to breach the blockade. Cumulative blockade enforcement: 6 ships stopped, 1 allowed through, 116 redirected.
• 🟢 OIL PRICE COLLAPSE — BRENT ~$91, WORST MONTH SINCE 2020: Brent fell ~2% Friday May 29 to ~$91.2/bbl (6-week low), down ~17–19% across May — the biggest monthly drop since 2020 — and ~20% off the 2026 peak. WTI settled ~$93.89. Driven by ceasefire optimism. From $109.26 (C88) → ~$91. War premium deflating fast. Price Lock LOOSENING — the largest single de-escalation signal of the crisis.
• 🔴 CEASEFIRE VIOLATED REPEATEDLY — US STRUCK IRAN MAY 25–26: US conducted "self-defense" strikes May 25–26 on Iranian missile launch sites and small boats attempting to lay mines, in response to what CENTCOM described as 24 hours of IRGC missile, drone and small-boat launches near Hormuz. Iran called it "a clear violation of the ceasefire," reserved the "legitimate and definite right to retaliate," and held the US "responsible for all consequences." The April ceasefire has been violated by both sides repeatedly through May even as the deal advanced.
• 🔴 UAE COVERTLY STRUCK IRANIAN ENERGY INFRASTRUCTURE (NEW BELLIGERENT DYNAMIC): It emerged that strikes on Iran's Lavan Island oil refinery and Sirri Island crude export facilities after the ceasefire began were carried out secretly by the United Arab Emirates. Late-May attacks on UAE territory were the first on UAE soil since the ceasefire. New energy-infrastructure damage on Iranian side; covert Gulf-state belligerency adds a Geographic Lock complication.
• 🟡 KHARG ISLAND SLICK — STILL UNRESOLVED (CARRIED FROM C88): No fresh independent sourcing this cycle on the May 6–8 ~52 km² slick off Kharg. Cause remains disputed (tanker ballast vs. aged Abuzar subsea pipeline). STALE — remains on escalation-indicator watch. Not classified as a strike.

1. Conflict Status

War Day 93 / Ceasefire Day 55 (Conflict began Feb 28, 2026; ceasefire effective ~April 7–8, 2026)

Operation Epic Fury — declared concluded by Rubio (May 6). US posture remained "deal, not military victory," but the ceasefire was repeatedly violated through May, with the US conducting self-defense strikes May 25–26 and Iran threatening retaliation.

Ceasefire status: Fragile but advancing toward formalization. The April ceasefire was never clean — US and Iranian forces exchanged strikes throughout May. The May 28–29 tentative deal would extend it 60 days and convert it into a negotiated framework, but Trump has not signed. Iran's state media said it has not been finalized.

Key developments this cycle (vs C88):

• May 23: Trump said the Iran deal reopening Hormuz was "largely negotiated, will be announced soon"
• May 25–26: US self-defense strikes on IRGC missile sites + mine-laying boats; Iran charged ceasefire violation, threatened retaliation (Brent +3% May 26)
• Late May: UAE attacks (first on UAE territory since ceasefire); revealed UAE secretly struck Iran's Lavan Island refinery + Sirri Island export facilities
• May 28: Trump rejected reports of Iran–Oman shared oversight of Hormuz shipping
• May 28–29: Tentative deal reached (60-day ceasefire extension + new nuclear talks); Trump ended meeting without final determination
• May 29: Trump announced end of the naval blockade
• May 30: US disabled another commercial ship breaching the blockade (enforcement continuing post-announcement)

Cumulative casualties (STALE — no fresh authoritative reporting located this cycle; carried from C88):

2. Strait of Hormuz — Operational Status

3. Tanker Attacks Log

Running total: 80+ commercial incidents, 41+ UKMTO reports since Feb 28 (no verified new commercial-vessel attacks this cycle beyond blockade-enforcement disablements and the covert UAE infrastructure strikes)

Append-only log — prior entries preserved in C88 and earlier reports.

4. Oil Prices

Forecast: Analysts expect Brent to hold $90–100 for the next couple of months until there is clarity on a lasting peace. This sits below the prior cycle's IEA "undersupplied through October" anchor — the market is now pricing resolution faster than the physical supply picture justifies, creating downside-surprise risk if the deal collapses.

5. Strategic Petroleum Reserves

6. Bypass Infrastructure

Note: Bypass physics are unchanged this cycle. The structural shortfall persists regardless of the diplomatic thaw — the only thing that closes the ~14–15 mb/d gap is physical reopening of the strait, which the tentative deal contemplates but has not delivered (transits still ~4–5/day). The UAE covert strikes on Iranian export facilities (Lavan/Sirri) marginally worsen Iran's own export capacity, irrelevant to bypass capacity but relevant to total available supply.

7. Maritime Insurance & Shipping

8. Shadow Fleet & Sanctions

Scale: ~1,400+ vessels (~25% global tanker fleet).

C115 updates:

• Sanctions-relief mechanism now in the deal: The tentative MOU would have the US relax sanctions and allow Iran to sell more oil during the 60-day window. This is the first prospective unwind of the sanctions architecture — it would reduce the economic rationale for the shadow fleet if implemented, though nothing is signed.
• US blockade enforcement continued through May 30 (6 stopped, 1 allowed, 116 redirected cumulative) — shadow/breach attempts ongoing right up to the blockade-end announcement.
• Iranian oil continued loading throughout the period (UANI tracking line from C88; no fresh total located — STALE).
• Trump rejected (May 28) an Iran–Oman shared-oversight model for Hormuz shipping — keeping enforcement framing unilateral/US rather than handing vetting to a Gulf condominium.

9. Country Response Matrix

10. Policy & Regulatory Actions

11. Key Metrics Dashboard

12. Convergence Assessment

(a) What Changed This Cycle (C115 vs C88)

1. Tentative US–Iran deal reached (May 28–29) [NEW — HIGH]. A written MOU now exists: 60-day ceasefire extension, new nuclear talks, Iranian no-weapon pledge, gradual blockade lift, sanctions relief allowing more Iranian oil sales. It is unsigned — Trump ended the May 29 meeting without a final determination, with "a couple of language points" outstanding and Iranian state media saying it's not finalized. This is the single most important development of the crisis to date, but its non-final status is the whole story: the system is at the threshold, not across it.

1. US naval blockade ended (May 29) [NEW — major loosening]. The April 13–May 29 blockade was announced over. Enforcement continued past the announcement (ship disabled May 30), and physical transit remains ~4–5/day — so this is a legal/political loosening ahead of physical normalization.

1. Oil price collapse — Brent ~$91, worst month since 2020 [NEW]. From $109 (C88) to ~$91, a ~17–19% May decline. The war premium is deflating in near-real-time on diplomatic signal. The market is now pricing resolution faster than the physical supply picture (still ~4–5 transits/day, GAP ~14–15 mb/d) or the insurance picture (P&I still absent) justifies.

1. Ceasefire repeatedly violated; US struck Iran May 25–26 [NEW]. Self-defense strikes on IRGC missile sites and mine-laying boats, prompting Iranian retaliation threats. The ceasefire has been porous throughout May even as the deal advanced — kinetic and diplomatic tracks running simultaneously in opposite directions.

1. UAE covert strikes on Iranian energy infrastructure [NEW]. Lavan Island refinery and Sirri Island export facility strikes were revealed to be UAE operations. A Gulf state covertly striking Iran's export infrastructure during a ceasefire is a new belligerent dynamic and adds Iranian-side infrastructure damage.

1. Oman floated, rejected as Hormuz co-overseer [NEW]. Trump rejected (May 28) an Iran–Oman shared-oversight model, keeping enforcement framing US-unilateral rather than a Gulf condominium.

1. Kharg slick unresolved [STALE]. No fresh sourcing; remains on escalation-indicator watch, not classified as a strike.

(b) Structural Locks Status (11)

Lock 1 — Price [LOOSENING — sharply]. Brent $109 → ~$91, worst month since 2020. War premium deflating on deal optimism. Caveat: running ahead of physical/insurance reality.

Lock 2 — Supply [LOOSENING — legal, not yet physical]. Blockade ended May 29; sanctions-relief mechanism in MOU. But transits still ~4–5/day, GAP ~14–15 mb/d unchanged. Direction positive; magnitude negligible so far.

Lock 3 — Insurance [HOLDING — the key holdout]. P&I still fully withdrawn, Day 55. No re-entry. Mine clearance 6+ months. This lock will outlast any signature.

Lock 4 — Labor [HOLDING]. ~22,500 trapped; ~800–1,000 vessels want to exit. No change.

Lock 5 — Duration [LOOSENING — strongest signal]. Tentative 60-day extension + new nuclear talks is the most concrete duration-shortening development of the crisis. Blocked only by Trump's pending signature.

Lock 6 — Nuclear [HOLDING — deferred, not resolved]. MOU includes no-weapon pledge but defers HEU disposal and enrichment into the 60-day window — the ~1,000 lb (≈440 kg) HEU stockpile and enrichment program remain unresolved. The hardest lock is postponed, not loosened.

Lock 7 — Geographic [MIXED]. Loosening: blockade end, deal track. Tightening: UAE covert strikes on Iran add a new belligerent line; May 25–26 US strikes; UAE territory hit.

Lock 8 — Capability [HOLDING]. No US minesweepers; active IRGC mine-laying; mine clearance 6 months. Project Freedom paused. Unchanged.

Lock 9 — Dual Chokepoint [HOLDING]. Suez ~60% below normal, structural. Resolving Hormuz does not resolve Suez.

Lock 10 — Leadership [LOOSENING slowly]. Iran negotiating a written MOU; multi-channel pressure (US direct, China, Oman). Engagement deeper than C88, but factional contradiction persists (state media vs. negotiators).

Lock 11 — Energy Infrastructure [HOLDING — worsened on Iran side]. Qatar Ras Laffan 17% cap / up to 5-yr repair unchanged. Added: UAE covert strikes on Iran's Lavan refinery + Sirri export facility. Kharg slick unresolved. This lock outlasts ceasefire by design — months-to-years repair timelines.

Tally: 5 holding, 4 loosening (Price, Supply, Duration, Leadership), 2 mixed/worsened (Geographic, Energy Infra). Nuclear holding-by-deferral.

(c) Critical Watch (Next Cycle)

• Trump signature — Does he sign the tentative deal, or do the "language points" collapse it? Single highest-leverage event.
• First P&I re-entry — The confirming structural signal. Absent = optimism is priced, not real.
• Transit normalization — Does the blockade-end translate into transits rising above the ~4–5/day floor?
• Iranian retaliation for May 25–26 strikes — Does Iran act on its threat, or absorb it to protect the deal?
• UAE–Iran escalation — Does the revealed covert strike dynamic provoke Iranian response against the UAE?
• Oil floor — Brent $90–100 expected; a deal collapse would snap the premium back violently given physics unchanged.
• Kharg slick sourcing — Still open from C88.

(d) Net Assessment

This is the first cycle in which the crisis has a credible off-ramp on the table. A written tentative MOU — 60-day ceasefire extension, new nuclear talks, an Iranian no-weapon pledge, and a phased blockade lift with sanctions relief — represents the most advanced diplomatic state since the war began Feb 28. The naval blockade was announced ended May 29, and the oil market has voted decisively: Brent fell ~17–19% in May, its worst month since 2020, deflating the war premium in near-real-time on deal optimism.

But the gap between the priced outcome and the structural reality is the defining tension of this cycle. The deal is unsigned — Trump ended the May 29 meeting without a final determination, with language still in flux and Iranian state media disowning finality. The physical strait is unchanged: ~4–5 transits/day versus ~150 pre-war, a ~14–15 mb/d unbridgeable supply gap, ~1,550 ships and ~22,500 seafarers still trapped. Most tellingly, no P&I club has re-entered Gulf coverage — the single strongest structural de-escalation indicator has not fired, and underwriters require a signed, holding ceasefire plus a 6-month mine-clearance horizon before it can. The nuclear lock is not resolved but deferred: the ~440 kg HEU stockpile and enrichment program are pushed into the 60-day negotiating window.

And the kinetic track never stopped. US self-defense strikes hit IRGC missile sites and mine-laying boats May 25–26; Iran charged a ceasefire violation and threatened retaliation; the UAE was revealed to have covertly struck Iran's Lavan and Sirri export facilities. The system is simultaneously assembling a peace framework and exchanging fire. The probability of formalization is materially higher than at C88 — but the same cycle that produced the deal also produced fresh strikes, a new covert Gulf belligerent, and continued mine-laying. The market has priced the deal; the locks have not released it. If Trump signs and a P&I club re-enters, this is the turn. If the language collapses, the premium snaps back hard against unchanged physics.

Scout 🏹 — C115 (catch-up cycle, 15-day gap from C88). Desktop substrate web sweep. Grok bridge: NO.
Sources: Wikipedia (2026 Strait of Hormuz crisis; 2026 US naval blockade of Iran; 2026 Iran war; 2026 Iran war ceasefire); PBS NewsHour; Axios; CNN; CNBC; NPR; NBC News; Newsweek; Al Jazeera; US News; Times of Israel; UN News; Scientific American; Middle East Council; Capital.com; Carra Globe. Casualty figures and several SPR/insurance/bypass values carried STALE from C88 pending fresh authoritative sourcing.