What is Greater Tunb Island, the strategic point in the Strait of Hormuz targeted by U.S. airstrikes?
Greater Tunb Island, located near the entrance to the Strait of Hormuz in the Persian Gulf, was targeted by a sustained wave of US airstrikes on coastal defence installations and missile storage sites.
The island is administered by Iran but is claimed by the United Arab Emirates, making it one of three long-disputed islands at the mouth of the strait.
Greater Tunb reportedly hosts a military airfield along with naval and missile assets used to monitor and, if needed, interdict shipping transiting the strait.
The strikes were described as intended to reduce the ability of installations on the island to threaten commercial shipping passing through the world's most important oil transit chokepoint.
The Iran-UAE Dispute over Abu Musa and the Tunbs
Greater Tunb, Lesser Tunb, and Abu Musa are three small islands at the mouth of the Strait of Hormuz whose sovereignty has been disputed between Iran and the United Arab Emirates since 1971. On 30 November 1971, immediately after the withdrawal of British protective forces from the Gulf, the Imperial Iranian Navy occupied all three islands. Iran claimed sovereignty over both the Tunbs and Abu Musa; the Tunbs had been claimed by the Emirate of Ras al-Khaimah and Abu Musa by the Emirate of Sharjah, both of which became founding members of the UAE shortly afterward and inherited the dispute.
Key Details
- Seizure date: 30 November 1971, coinciding with the end of the British protectorate over the Trucial States
- Sharjah accepted an interim 1971 arrangement with Iran to share offshore oil revenue around Abu Musa, but no equivalent arrangement covers the Tunbs, over which Iran exercises full control
- The UAE has sought to bring the dispute before the International Court of Justice; Iran has consistently refused third-party adjudication, treating the islands as non-negotiable domestic territory
- The dispute is raised periodically at the UN Security Council and by the Gulf Cooperation Council (GCC), which backs the UAE's claim, without resolution
Because Iran, not the UAE, holds physical control of Greater Tunb, it is Iran's military infrastructure on the island — not a UAE-administered facility — that was targeted, reflecting the island's role in Iran's actual (though internationally contested) control over this stretch of the strait.
Strategic Geography of the Strait of Hormuz Approaches
The Strait of Hormuz connects the Persian Gulf to the Gulf of Oman and the wider Arabian Sea, separating Iran's southern coast from Oman's Musandam Peninsula. Greater Tunb, Lesser Tunb, Abu Musa, Qeshm, Larak, Hormuz, and Sirri form a chain of Iranian-administered or Iranian-controlled islands positioned along and near the strait's northern approaches, often described as constituting Iran's layered "defensive arc" for monitoring and, if necessary, contesting control of the waterway.
Key Details
- Only two countries border the strait directly: Iran (north) and Oman (south, via the Musandam Peninsula)
- The strait narrows to roughly 39 km at its narrowest point, with navigable shipping lanes only about 3 km wide in each direction
- Roughly a fifth of global seaborne oil trade and a substantial share of global LNG trade transits the strait
- Islands such as Greater Tunb, positioned close to the strait's entrance, allow radar coverage, anti-ship missile basing, and fast-attack-craft staging over the shipping lanes — a concept sometimes compared to "unsinkable aircraft carriers"
Targeting installations on Greater Tunb specifically aims at this outer layer of Iran's monitoring and interdiction capability near the strait's mouth, distinct from mainland Iranian coastal defences further inside the Persian Gulf.
Territorial Disputes over Islands and International Law
Sovereignty disputes over small, low-population islands with disproportionate strategic or resource value are a recurring pattern in international law, generally addressed through frameworks such as the UN Convention on the Law of the Sea (UNCLOS, 1982) for maritime entitlements, and through International Court of Justice (ICJ) adjudication of the underlying territorial sovereignty question, where the parties consent to jurisdiction.
Key Details
- UNCLOS (1982, in force 1994) governs entitlements such as territorial sea (12 nautical miles), exclusive economic zone (200 nautical miles), and continental shelf claims that flow from confirmed island sovereignty — but does not itself resolve underlying sovereignty disputes
- ICJ jurisdiction is generally consensual; a state cannot be compelled to litigate a sovereignty dispute unless it has accepted the Court's jurisdiction for that matter, which explains why Iran's refusal has kept the Abu Musa/Tunbs dispute unresolved for over five decades
- Comparable prolonged island sovereignty disputes include the Kuril Islands (Japan-Russia) and the Senkaku/Diaoyu Islands (Japan-China)
The absence of a binding international mechanism to resolve the Tunbs dispute is precisely why the islands' status has remained frozen since 1971, leaving them under continuous Iranian military use and, now, a target of direct military action by a third party.
- Disputed islands: Greater Tunb, Lesser Tunb, and Abu Musa — claimed by the UAE, controlled by Iran since 1971
- Seizure date: 30 November 1971, following British withdrawal from the Trucial States
- Strait of Hormuz: separates Iran (north) from Oman's Musandam Peninsula (south); narrowest point approximately 39 km
- Approximate share of global seaborne oil trade transiting the strait: about one-fifth (roughly 15 million barrels/day of crude oil)
- Governing maritime law framework: UNCLOS (1982, in force 1994)
- The UAE has sought ICJ adjudication of the dispute; Iran has not accepted jurisdiction over the matter