IRGC Navy

Distinct from Iran's conventional navy (IRIN), the IRGC Navy operates fast-attack craft, mines, and anti-ship missiles in the Persian Gulf's shallow southern littoral. Its main base is Bandar Abbas, directly overlooking the Strait of Hormuz. On 17 April 2026 it published a formal four-condition transit order; by May 2026 it was running the Persian Gulf Strait Authority registration system, requiring vessels to declare cargo, crew nationalities, and flag history. On 11 June 2026 the IRGC Navy posted an order to its official Telegram channel barring all maritime traffic through the Strait: the first formal closure declaration of the war and a military veto of the diplomatic track its civilian government was still pursuing. The Navy declaration said two vessels were hit for defying the order, naming none; CENTCOM rejected the closure publicly and said commercial shipping continues transiting normally.

The force entered the 2026 conflict as Iran's primary asymmetric maritime instrument. Before hostilities it held approximately 65 operational surface vessels; CENTCOM reported destroying 130+ in what it described as the largest naval attrition campaign since the Second World War. Commander Admiral Tangsiri and intelligence chief Behnam Rezaei were killed in an Israeli airstrike on Bandar Abbas on 27 March 2026, yet the blockade held and the toll system was subsequently codified into domestic law. On 4 July 2026, Rear Admiral Ali Azmaei surfaced as Tangsiri's successor via a public message issued during Khamenei's funeral proceedings; no appointment decree has been published, which Iran International reads as part of a wider pattern of undocumented senior command changes since Khamenei's death. On 25 May 2026, CENTCOM struck Bandar Abbas again, eliminating two IRGC mine-laying boats caught operating in the Strait and destroying a surface-to-air missile site.

The IRGC Navy's 11 June closure order is a structural tension with the late-May MoU framework, which required Hormuz to reopen as part of any deal. The Decentralised Mosaic Defence doctrine devolves launch and mine-laying authority to 31 autonomous provincial commands, meaning Iran's civilian negotiators cannot credibly guarantee boats will stop even when they want a deal. For European energy markets and Gulf oil exporters, the force acting as enforcement body for a closure that contradicts Iran's own diplomatic commitments is the central Hormuz uncertainty: even a signed Ceasefire may not deliver transit.