What Happened
- Iran's Islamic Revolutionary Guard Corps (IRGC) warned that any vessel passing through the narrow Strait of Hormuz would be targeted, effectively declaring a maritime exclusion zone in one of the world's most critical waterways.
- Multiple ships were attacked in the Gulf region following the start of the Iran war on February 28, 2026, with Iran deploying fast-attack craft, mines, and missiles against commercial and military vessels.
- Tanker traffic through the Strait of Hormuz dropped by approximately 70% initially, then to near-zero as the IRGC escalated attacks, with over 150 vessels anchoring outside the strait to avoid targeting.
- The attacks constituted a form of "maritime siege" — a deliberate strategy by Iran to leverage its geographic control of the strait as a bargaining chip in the broader conflict.
- War risk insurance designations for the Persian Gulf and Gulf of Oman shifted, causing freight rates to spike and many vessel owners to declare force majeure or refuse new voyage charters into the region.
Static Topic Bridges
The IRGC: Structure, Role, and Designation
The Islamic Revolutionary Guard Corps (IRGC) is Iran's ideologically-driven parallel military force, established after the 1979 Islamic Revolution to protect the revolutionary system. It is distinct from Iran's regular armed forces (Artesh) and reports directly to the Supreme Leader. The IRGC has ground forces, aerospace forces, a navy, the Quds Force (external operations), and the Basij (domestic paramilitary).
- IRGC Navy has approximately 20,000 sailors; controls fast-attack craft, submarines, anti-ship missiles, and naval mines
- IRGC Navy doctrine: asymmetric "guerrilla navy" — swarm tactics, hit-and-run attacks using small fast-attack craft (FACs) and speedboats in the confined Persian Gulf
- Designated a Foreign Terrorist Organisation (FTO) by the US in April 2019
- The IRGC also controls Iran's ballistic and cruise missile programme through its Aerospace Force
- In 2019, IRGC was accused of limpet mine attacks on four oil tankers in the Gulf of Oman near Fujairah
Connection to this news: The ship attacks described are consistent with the IRGC Navy's established asymmetric warfare doctrine — using fast-attack craft and mines to threaten much larger conventional forces in the confined Persian Gulf waters.
Freedom of Navigation Operations (FONOPS) and Maritime Security
Freedom of Navigation Operations are naval passages conducted by states to challenge what they consider excessive maritime claims by coastal states. The US, UK, and other navies conduct FONOPS to uphold the international maritime legal order under UNCLOS.
- Under UNCLOS Part III (Articles 37-44), transit passage through international straits (including Hormuz) is guaranteed to all vessels
- Iran's position: it claims the Strait of Hormuz is within its territorial waters and requires prior notification for warships — a position not accepted under UNCLOS transit passage rights
- The International Maritime Organization (IMO) Traffic Separation Scheme (TSS) for the Strait of Hormuz designates two 3-km-wide shipping lanes (inbound and outbound), separated by a 3-km buffer
- Attacks on commercial vessels in international waters or straits constitute violations of UNCLOS and international humanitarian law
Connection to this news: Iran's attacks on vessels in the Strait of Hormuz directly violated the transit passage rights guaranteed under UNCLOS, making the conflict a landmark test of the international maritime legal order.
Tanker Wars: Historical Precedent
The current Hormuz crisis echoes the "Tanker War" phase of the Iran-Iraq War (1984-1988), when both Iraq and Iran attacked oil tankers in the Persian Gulf to deny each other oil revenues. The US Navy conducted Operation Earnest Will (1987-1988) to protect Kuwaiti tankers by reflagging them as US vessels.
- During the 1984-1988 Tanker War, over 400 tankers were attacked, killing hundreds of sailors
- The US, UK, and other Western navies eventually deployed naval escorts to protect shipping
- In 2019-2020, the US established Operation Sentinel and the International Maritime Security Construct (IMSC) in response to IRGC harassment of Gulf tankers
- The 2026 IRGC attacks followed a similar doctrine to the 1980s Tanker War but with more sophisticated weapons (anti-ship missiles, drone swarms)
- The IMO Joint War Committee (JWC) designated the Persian Gulf as a high-risk area during both episodes
Connection to this news: The pattern of Iranian attacks on Gulf shipping in 2026 directly mirrors the 1984-1988 Tanker War precedent — the UPSC may test this historical comparison under GS2 international relations or GS3 internal security.
Key Facts & Data
- Tanker traffic through the Strait of Hormuz dropped ~70% initially, then to near-zero by early March 2026
- Over 150 vessels anchored outside the strait to avoid IRGC targeting
- IRGC designated a Foreign Terrorist Organisation by the US in April 2019
- The IMO Traffic Separation Scheme designates two 3-km-wide shipping lanes in the Strait of Hormuz
- During the 1984-1988 Iran-Iraq Tanker War, over 400 commercial vessels were attacked
- US conducted Operation Earnest Will (1987-88) to escort reflagged Kuwaiti tankers
- The IRGC Navy uses fast-attack craft, anti-ship missiles, limpet mines, and naval mines