The IRGC struck the oil tanker Prima with a drone in the Strait of Hormuz on Saturday after the vessel ignored repeated IRGC Navy warnings about Iran's declared transit ban. As with the Louise P, the Guards identified the Prima by name and claimed responsibility. The stated justification was different: the Louise P was targeted for perceived American ownership in the open Gulf; the Prima was hit for attempting to pass through the strait without IRGC authorisation.
The two attacks establish complementary targeting regimes. In open Gulf waters, vessels face strikes based on perceived national affiliation. In the strait itself, any ship attempting transit without IRGC permission is subject to attack regardless of flag or cargo. Under the transit passage provisions of UNCLOS Part III — generally accepted as customary international law — ships have the right to continuous, expeditious passage through international straits without prior authorisation. Iran's enforcement of a vessel-by-vessel permission regime contradicts this framework. The legal distinction is immaterial to the master of a tanker facing an inbound drone.
During the 1984–1988 Tanker War, Iran and Iraq attacked more than 400 commercial vessels over four years. Neither side publicly identified targets by name or articulated enforcement doctrines — those strikes were largely deniable, often misattributed, and conducted without published rationale. Nine days into this conflict, the IRGC has surpassed that precedent: naming vessels, claiming attacks, and stating distinct justifications for each. The United States eventually responded to the Tanker War with Operation Earnest Will, escorting reflagged Kuwaiti tankers through The Gulf from 1987. No comparable programme exists now — the US Navy has not conducted a single escorted commercial passage. China, by contrast, has entered direct negotiations with Tehran for a bilateral safe-passage arrangement. If formalised, the result is a two-tier Strait: open for Chinese-linked commerce, closed to everyone else — a commercial partition of the world's most important oil chokepoint managed by Beijing and Tehran without reference to the international legal order that governed it for decades.
