What Happened: A U.S. aircraft recorded five armed vessels operated by the Iranian Islamic Revolutionary Guard Corps (IRGC) attempting — and ultimately failing — to seize a British oil tanker crossing into the Strait of Hormuz on July 10, Reuters reported, citing unnamed U.S. officials. The British oil tanker was being escorted from the rear by the Royal Navy frigate HMS Montrose, which reportedly gave a verbal warning and trained its guns on the approaching IRGC vessels before the Iranians dispersed.
Why It Matters: Iranian President Hassan Rouhani issued a warning on state television earlier on July 10, responding to an incident last week in which British Royal Marines seized an Iranian oil tanker transporting crude oil to Syria. He said: "You [the United Kingdom] are the initiator of insecurity and you will realize the consequences later." A U.S. administration official claimed in a Foreign Policy report on July 9 that the UK, along with France, have shown interest in participating in Operation Sentinel, a U.S.-led maritime initiative to protect vessels transiting the Strait of Hormuz from Iranian harassment. Tehran's attempted retaliation against a British oil tanker increases the likelihood of the United Kingdom participating in the mission, increasing the Royal Navy's presence in the area.
Background: Two previous attacks on oil tankers in the crucial chokepoint, an Iranian shootdown of an American drone, and Iran's moves to incrementally restart parts of its nuclear program reveal Tehran's concerted attempt to push back against the United States' maximum pressure campaign — and Iran's willingness to risk military confrontation in the Persian Gulf.