On Thursday, June 13, two ships were damaged within forty-five minutes by (current evidence suggests) limpet mines, while transiting the Gulf of Oman at the mouth of the Strait of Hormuz. The Japanese product tanker, Kokuka Courageous sustained damage from either a limpet mine or a projectile, just as Prime Minister Shinzo Abe met with Iranian Supreme Leader Ayatollah Ali Khamenei in Tehran to try to reduce regional tensions. The Front Altair, also a tanker, suffered far more severe damage to its starboard hull, including a hole at the waterline, which – it has been suggested – was the result of a torpedo strike. This is very difficult to confirm – torpedoes tend to cause much more significant damage, and the damage sustained by Front Altair might also be consistent with a moored or floating mine strike, or the detonation of an attached limpet mine. Both ships caught fire and their crews abandoned ship. Four ships were also damaged by limpet mines off the coast of Fujairah on May 12, 2019. A UAE inquiry pinned responsibility on an ‘unidentified state actor.’
World oil prices increased as daily freight rates for oil supertankers climbed as much as fifty percent to reflect the heightened risk. Insurance rates for a seven-day transit have increased fifteen percent. Some seventy of the world’s supertankers are in the region – ten percent of global capacity – but many remain idle due to the threat. The United States blamed Iran for the attacks, and indeed there is evidence that points to Iranian involvement. The UK also attributes responsibility to Iran. Iran has denied responsibility, and Iranian Foreign Minister Javad Zarif responded on twitter that the United States or its allies were likely behind the assaults and that the charge was ‘[without] a shred of factual or circumstantial evidence.’
The United States has pledged to keep the Strait of Hormuz (SOH) open to traffic. Secretary of State Mike Pompeo attributed the attacks to Iran based upon ‘intelligence, the weapons used, the level of expertise needed to execute the operation, recent similar Iranian attacks on shipping, and the fact that no proxy group operating in the area has the resources and proficiency to act with such a high degree of sophistication.’ On June 17 he doubled down, promising to present in the coming days ‘lots of data, lots of evidence’ linking the attacks to Iran. President Trump stated flatly, ‘Iran did do it.’ U.S. Central Command released a video which appears to show an Iranian Revolutionary Guard Corp Navy (IRGCN) patrol boat removing an unexploded limpet mine from the Kokuka Courageous. Trump added, ‘I guess one of the mines didn’t explode and it’s probably got essentially Iran written all over it… It was them that did it.’
In this piece, we explore the available evidence for attribution in light of the international law on point. May the attacks be attributed to Iran, and if not, what additional evidence would have to be produced? And once (if) attribution of the attacks is made out, what measures may affected states then take in response? Since there is no evidence that there exists an international armed conflict under Common Article 2 of the Geneva Conventions, we do not address international humanitarian law, although in the last few days the shoot down of a US UAV and reports of a bombing mission switch off are starting to complicate this assessment.