US-Iran strikes resume as Hormuz traffic remains below one-tenth of baseline

Bottom Line

Another direct US-Iran exchange is likely within 72 hours, with moderate confidence. The assessment follows the reported 1 September US strikes on IRGC targets in Iran, Iranian reports of retaliation, and the Jordanian Armed Forces' report that eight missiles directed towards King Hussein and Al-Azraq air bases were intercepted. The latest target set, damage and casualty claims remain disputed, so a very likely judgement is not warranted.

Commercial passage through the Strait of Hormuz is likely to remain severely constrained through 15 September. For traffic volume, severe constraint means a rolling Kpler count below 10 per cent of the cited pre-conflict baseline of about 100 visible commodity vessels per day. The strait is not assessed as physically closed because selected transits continue, Saudi Aramco has resumed some loading, and the number of distinct Khasab tanker incidents remains unresolved.

Russia is very likely to continue high-tempo air attacks against Ukraine. Germany's public attribution of the Leipzig/Halle Airport drone attack to Russia is likely to expand European countermeasures, but the underlying technical evidence remains unpublished. Gaza, Lebanon, Sudan and Niger remain on their prior trajectories rather than showing a confirmed decisive change during this reporting window.

Key Developments

US-Iran and Jordan

Reported facts: US Central Command reported strikes on IRGC targets in Iran on 1 September. Iranian state-linked media reported missile and drone attacks against US-linked positions and explosions at Qeshm Island, Bandar Abbas, Chah Bahar, Jask and Sirik. Iranian state media attributed four deaths and 50 injuries near Sirik to a strike, but no independent damage assessment is available. The Jordanian Armed Forces reported intercepting eight missiles directed towards King Hussein and Al-Azraq air bases.

Assessment: Another direct exchange is likely within 72 hours. The main escalation path is a further US strike against Iranian launchers, IRGC facilities or maritime-denial assets, or an Iranian missile, drone or maritime action against US-linked positions. The evidence does not establish a US decision to conduct a sustained regional air campaign or an Iranian decision to conduct repeated large-scale attacks.

Strait of Hormuz

Reported facts: Kpler recorded about five visible commodity vessels per day over the weekend, compared with about 100 per day before the conflict. Windward reported a weekly high of 21 ships per day, but the source material does not establish that the Windward figure measures the same vessel category or geographic area. UKMTO and maritime trade reporting described incidents involving two vessels near Khasab, Oman.

Assessment: The record supports at least one tanker incident near Khasab and reports a second vessel, but it does not establish whether the accounts describe one event, two events or overlapping reports. The attacker remains unidentified. The Joint Maritime Information Center continues to warn about drifting or uncharted mines, while INTERTANKO states that mine clearance alone does not assure passage without interference.

Ukraine

Reported facts: The 1 September Russian wave involved 218 strike drones, about 72 of them jet-powered, plus Iskander-M, KN-23, S-400, Zircon, Kalibr, Kh-31P and S8000 Banderol missiles. Ukrainian air-defence authorities reported 199 targets destroyed or suppressed, impacts at 28 locations and debris at 10 others. The daytime phase included 99 additional strike drones, and reports identified casualties and damage in Kyiv, Boryspil and Odesa Oblast. The 28 to 29 August series involved more than 550 drones and missiles over more than 28 hours.

Assessment: The 1 September attack was smaller than the 28 to 29 August series by total systems, but it extended the air campaign to a sixth consecutive day and included a layered mix of one-way attack drones, ballistic missiles, cruise missiles and anti-radiation weapons. The mix is consistent with pressure on Ukrainian air-defence sensors and interceptors while also striking urban, railway, electricity and port infrastructure. Russian strikes are very likely to continue over the next 14 days.

Germany and European hybrid activity

Reported facts: Germany publicly attributed the 4 August Leipzig/Halle Airport drone attack to Russia, raised its threat assessment from general to high, and announced the closure of Russia's consulate in Bonn and the Russian House in Berlin. Leipzig/Halle hosts NATO's Strategic Airlift International Solution operation. NATO Secretary General Mark Rutte and a US defence official had previously supported a Russian attribution. German authorities have not published the technical evidence, and the reported devices near a Brandenburg power substation remain unattributed.

Assessment: The German attribution is a public government finding, not independently demonstrated responsibility in the absence of published technical evidence. It is likely to strengthen German, NATO and EU coordination on sanctions, facility protection and counter-disinformation measures. Its effect on Russian behaviour is uncertain. A direct conventional Russian attack on a NATO member remains very unlikely over the next three months.

Other theatres

• Gaza: OCHA and Palestinian medical sources continued to report Israeli strikes and deaths on 31 August and 1 September. Israeli hostilities are very likely to continue, and severe humanitarian conditions are very likely to persist. Confidence is high for continuation and humanitarian deterioration.
• Southern Lebanon: UNIFIL continues to report Hezbollah activity and Israeli retaliation. Israel-Hezbollah exchanges are likely to continue, while a direct wider war remains roughly even chance over the next 1 to 3 months. Confidence is moderate.
• Sudan: SAF-RSF fighting continues around Kordofan, Darfur and Blue Nile, including pressure around El Obeid, Bara and El Fasher. Active combat is very likely to continue through September. Confidence is high.
• Niger: General Abdourahamane Tchiani's forces almost certainly retain control of Niamey after the 29 August mutiny. JNIM and Islamic State affiliates are very likely to remain active in Tillaberi, Dosso and Diffa. Confidence is moderate for the capital-control judgement and the external jihadist threat.

Analysis

Change since the prior briefing

• US-Iran: The prior briefing assessed another direct exchange as likely through 14 September. The new assessment is also likely, but the timing is now narrowed to within 72 hours because a further US strike was reported on 1 September after the Larak Island strike and Iranian missile launches towards Jordan. The probability category has not been raised to very likely because the latest strike scope and Iranian retaliation remain partly dependent on interested-party reporting.
• Hormuz: No material change in the judgement that commercial passage will remain restricted through 15 September and that a complete closure is unlikely. The current brief refines the term severely constrained by separating traffic volume, safe passage, insurance and export throughput. Kpler's five-vessel weekend count is the primary volume measure; Windward's 21-vessel figure is not directly comparable.
• Ukraine: No material change in the very likely forecast of continued Russian air attacks. The new evidence supports a high-tempo, multi-day campaign, but does not show that the 1 September wave exceeded the 28 to 29 August series in total volume. Ukrainian long-range strikes against Russian refineries, ports and military infrastructure remain likely.
• Gaza: No material change. Israeli strikes and other hostilities remain very likely, and severe humanitarian conditions are very likely to persist. OCHA, WHO, WFP and UNICEF reporting remains the strongest basis for the humanitarian assessment.
• Lebanon: No material change. Israel-Hezbollah exchanges remain likely, while a direct wider war remains roughly even chance. UNIFIL reporting supports the continuation judgement, but Hezbollah's decision-making remains opaque.
• Sudan: No material change. SAF-RSF combat is very likely to continue, with North Kordofan, North Darfur and Blue Nile the main pressure points. Local control around El Fasher, Bekouri and Sarkam remains contested.
• Niger: No material change. Tchiani's forces almost certainly retain central Niamey, while the mutiny continues to indicate military-cohesion problems. JNIM and Islamic State affiliates remain a separate pressure outside the capital.
• Energy exports: No material change. Gulf exports are likely to remain below normal, but Saudi Aramco's resumed loading from inside the strait demonstrates that disruption is severe rather than total. QatarEnergy and other exporters remain exposed to routing, insurance and delivery delays.
• Europe: The German public attribution of Leipzig/Halle is a new development. It changes the policy and attribution environment more than the underlying forecast of continued Russian-linked hybrid activity, which was already assessed as very likely.

Source quality and contested reporting

The source package contains 242 graded source entries across 24 briefs. Ninety-four entries are in the highest reliability tier, 74 in the next tier, 37 in a medium tier, 17 in each of two lower tiers, and three in the lowest reliability tier. These entries are not necessarily independent because several reports repeat a single official or local-media origin.

The core judgements on the existence of the US-Iran exchange, the Jordanian interceptions, the Hormuz traffic decline, the 1 September Russian air campaign and the German attribution are supported by combinations of official, UN, maritime, wire-service and major-media reporting. Confidence is lower for claims that originate with interested parties and lack independent corroboration. CENTCOM is the originator for the US strike account; Iranian state-linked media are the originators for Iranian damage and casualty claims; the Jordanian Armed Forces are the originator for the eight-interception account; and UKMTO and maritime reporting are the main sources for the Khasab incidents. No independent imagery or third-party damage assessment resolves the Iranian port claims, the attacker responsible for the Khasab incidents, the number of affected vessels or the reported Al Minhad strike.

Germany's Leipzig/Halle attribution has support from German officials, NATO leadership, a prior US defence assessment and major-media reporting, but Germany has not released the technical basis. The attribution therefore supports a moderate-confidence assessment of European policy effects, not a high-confidence independent finding of responsibility. NASA FIRMS data record heat rather than cause, and the narrow AIS samples supplied for Taiwan and other locations cannot establish military activity or shipping disruption.

Stakeholder implications

• QatarEnergy: Continued low Hormuz traffic and insurance restrictions are likely to affect LNG loading windows, vessel allocation and delivery schedules. A verified transit mechanism would reduce scheduling uncertainty before it restored normal throughput.
• Saudi Aramco: Resumed loading inside Hormuz indicates partial operating capacity, but the Sidr incident and the use of Yanbu, Ain Sukhna and the SUMED pipeline expose crude and product deliveries to routing and insurance decisions. Further tanker damage would increase reliance on northern Red Sea routes and alternative storage.
• Shipowners and tanker operators: Operators face a choice between restricted Hormuz transit, protected passage and Cape of Good Hope diversion. The reported extension of some voyages by more than 30 days and high VLCC charter rates indicate that route selection is already affecting fleet availability. AIS gaps, convoy participation and cargo declarations are likely to influence risk pricing.
• Marine insurers and P&I clubs: New mine warnings, unresolved tanker attacks or a formal Iranian boarding policy would increase war-risk premiums and could produce exclusions for Hormuz transit. A jointly authenticated route and independent incident verification would reduce, but not eliminate, underwriting uncertainty.
• Jordanian Armed Forces: King Hussein and Al-Azraq air bases remain exposed to further Iranian missile or drone attempts because they host US-linked activity. Additional interceptions, debris recovery or damage would affect air-defence alerting and base-protection decisions.
• UAE Ministry of Defence: The reported Iranian drone interception over UAE territorial waters and the disputed Al Minhad claim create a separate warning channel. Verified damage at Al Minhad or further Iranian launches would raise pressure on UAE air-defence and US force-protection postures.
• US Central Command: CENTCOM faces simultaneous force-protection requirements around Jordan, the UAE, Oman and maritime routes near Larak Island. A confirmed US or allied fatality, a minefield or a new IRGC launch preparation would narrow the distinction between limited retaliation and sustained regional operations.
• India and Pakistan: Continued low Hormuz traffic is likely to raise freight, insurance and import-cost exposure for crude, products and LNG. A three-day return above 25 per cent of the cited baseline would indicate partial relief, while near-zero traffic would increase inventory and refinery-scheduling pressure.
• European governments and NATO: Germany's attribution increases the political basis for countermeasures against Russian-linked sabotage and information operations. A second drone incursion or a NATO casualty would test whether current measures remain below direct military retaliation.

Indicators & Warnings

• US-Iran kinetic escalation: Early indicators are CENTCOM force-protection notices, Jordanian air-defence alerts, UAE intercept reports and IRGC mobilisation statements. Confirmation would be a new named strike, launch or verified damage. Forty-eight hours without a reported launch or strike plus a jointly announced ceasefire would weaken the assessment. Collection streams are reviewed hourly. Horizon: 24 to 72 hours.
• Iranian maritime coercion: Monitor IRGC Navy transit warnings, boarding reports, mine-clearance activity and closure notices. A verified boarding, mine deployment or formal closure would indicate movement towards the physical-closure alternative. A jointly authenticated route with three days of interference-free transits would weaken the restriction assessment. Review every six hours. Horizon: 24 to 72 hours.
• Hormuz traffic: Use Kpler's daily commodity-vessel count as the primary measure. Below 10 vessels per day for three consecutive days supports severe volume constraint; above 25 vessels per day for three days indicates partial recovery. Windward's 21-vessel weekly high is supplementary only because its method is not comparable. Review daily. Horizon: 24 hours to 15 September.
• Khasab tanker incidents: Seek UKMTO updates, vessel-owner statements, crew-status confirmation, AIS records and geolocated imagery for Sidr and Senegal Prosperity. Independent hull damage, distress records or a named attacker would confirm the incident and improve attribution. Normal tracking and owner statements without damage would weaken the reports. Review every six hours. Horizon: 24 to 72 hours.
• Energy and insurance transmission: Monitor insurer exclusions, war-risk premiums, QatarEnergy schedules, Saudi Aramco loading notices and VLCC rates. A blanket Hormuz exclusion by a major insurer, a QatarEnergy delay or a Saudi Aramco suspension would confirm worsening commercial risk. Brent above 90 US dollars per barrel alone is not diagnostic because it reflects broader market conditions. Review twice daily. Horizon: 72 hours to two weeks.
• Russian air campaign: Compare the next rolling 72-hour drone count with the 1 September total of 218. Another wave near that level, or two consecutive waves above 109 drones, combined with missile launches and infrastructure damage, would confirm recurrence. Seven days of isolated attacks would weaken the high-tempo assessment. Review every 12 hours. Horizon: 24 hours to 14 days.
• NATO airspace and Russian hybrid activity: Monitor Estonian, Romanian and Polish defence ministries, NATO notices and German investigations for another incursion, sabotage event or information operation attributed to Russia. A second incident within 30 days, NATO weapons use or an Article 4 consultation would indicate escalation. No further incident for 30 days would weaken the continuation assessment. Review daily. Horizon: one to four weeks.
• Gaza, Lebanon, Sudan and Niger: Monitor OCHA and the IDF for a Gaza City ground operation or sharp casualty increase; UNIFIL and Lebanese Armed Forces for Hezbollah attacks causing Israeli deaths or Israeli strikes on Beirut; SAF and RSF reporting for renewed fighting around El Obeid, Bara, El Fasher or Blue Nile; and Nigerien security reporting for senior-officer arrests, renewed fighting around Air Base 101 or attacks by JNIM and Islamic State affiliates near Tillaberi, Dosso or Diffa. Review daily. Horizon: 24 hours to 30 days.

Alternatives

The alternatives below contain two separate mutually exclusive probability sets. The US-Iran set sums to 100 per cent within that question. The Hormuz set also sums to 100 per cent within its question. Probabilities are not additive across the two sets because military and maritime outcomes can occur simultaneously.

US-Iran outcome set through 15 September

• Limited reciprocal exchanges without a successful mass-casualty attack, 45 per cent, roughly even chance: Washington and Tehran continue calibrated strikes or attempted strikes while avoiding a sustained regional campaign. New limited attacks on launchers, drones or maritime-denial assets would confirm this path.
• Mediated pause with limited maritime arrangements, 25 per cent, unlikely: Pezeshkian's conditional diplomacy becomes a jointly implemented arrangement accepted by Iran, the United States, Oman, Qatar and relevant Gulf states. A signed text naming routes, escorts and monitoring would confirm it.
• Sustained regional campaign after a deliberate successful attack, 15 per cent, unlikely: A deliberate Iranian, IRGC-affiliated or partner attack causes US or allied fatalities, or the United States deliberately strikes Iranian ports, energy infrastructure or command nodes. Repeated strikes over several days, proxy attacks by the Houthis or Hezbollah, or a formal rules-of-engagement change would confirm the transition.
• Deliberate restraint with no further kinetic exchange, 10 per cent, very unlikely: Both governments prioritise force preservation and economic pressure. Seven days without reported launches or strikes, accompanied by public restraint orders and functioning talks, would confirm it.
• Accidental or misattributed engagement followed by containment, 5 per cent, very unlikely: A mine, air-defence engagement, navigation error or unauthorised proxy action causes damage, but the parties avoid deliberate retaliation. Conflicting attribution, rapid hotline activity and no repeat incident within 72 hours would support this path.

Hormuz outcome set through 15 September

• Traffic remains below 10 per cent of baseline because of commercial avoidance, 40 per cent, roughly even chance: Mine warnings, insurance restrictions and uncertainty over Iranian boarding rules continue to deter operators even without a new verified attack. Kpler counts below 10 vessels per day for three days would confirm it.
• Verified convoy or transit arrangement produces partial reopening, 30 per cent, unlikely: Oman, Qatar, Iran and the United States agree on route control and monitoring while the wider conflict continues. Three days of independently verified commercial transits above 25 vessels per day would confirm it.
• Physical closure or near-closure after confirmed mining, boarding or multiple attacks, 20 per cent, unlikely: Iran or an aligned actor prevents passage through mining, boarding, missile attack or a closure notice, followed by US force-protection or clearance operations. Verified mines, multiple boardings or traffic approaching zero for three days would confirm it.
• Commercial traffic recovers despite unresolved political tension, 10 per cent, very unlikely: Shipowners and insurers judge physical risk manageable without a formal settlement. Kpler counts above 25 vessels per day for three days, normalising AIS coverage and stable insurance terms would confirm it.

Outlook

Another direct US-Iran exchange is likely within 72 hours, with moderate confidence. A confirmed launch preparation, new force-protection deployment or rules-of-engagement change would raise the probability. A jointly announced pause accompanied by 48 hours without launches or strikes would lower it.

Hormuz traffic is likely to remain severely constrained through 15 September, with moderate confidence. The physical waterway will remain partially active, but traffic volume, safe passage and insurance availability are likely to remain below normal. A verified minefield, boarding or port-closure notice would indicate movement towards near-closure. A jointly authenticated transit mechanism and three consecutive days above 25 per cent of the cited baseline would indicate partial recovery.

Russian attacks against Kyiv, Kyiv Oblast, Odesa Oblast and Ukrainian infrastructure are very likely to continue over the next 14 days, with high confidence. Ukrainian strikes against Russian refineries, ports, airbases and logistics sites are likely over the same period, with moderate confidence. A decisive Russian or Ukrainian operational breakthrough remains unlikely through November.

Israeli hostilities in Gaza are very likely to continue, with severe humanitarian conditions very likely to persist. Israel-Hezbollah exchanges are likely to continue, SAF-RSF combat is very likely to persist through September, and JNIM and Islamic State affiliates are very likely to remain active in western and southeastern Niger. These continuity judgements are supported by the absence of a ceasefire, continuing incident reporting and no confirmed political settlement in any of the four theatres.