Abu Musa and the Tunbs: The Occupied Islands That Sit at the Strait's Entrance
Three small islands sit near the entrance of the Strait of Hormuz. Abu Musa belongs to the emirate of Sharjah. Greater Tunb and Lesser Tunb belonged to Ras al-Khaimah. In November 1971, two days before the British protectorate over the Trucial States expired and three days before the United Arab Emirates came into formal existence as an independent nation, Iranian forces occupied all three. Greater Tunb was taken by force, killing several Ras al-Khaimah police officers who attempted to resist. Abu Musa was occupied under a memorandum of understanding with Sharjah that Iran has since interpreted in ways that effectively amount to full occupation. The UAE has never accepted any of this. The dispute is over fifty years old and shows no sign of resolution.
The strategic significance of the islands is not accidental. Iranian planners in 1971 understood — as the British had understood before them — that control of islands at the strait’s entrance provides observation posts, military basing locations, and chokepoint leverage that otherwise would not exist. Greater Tunb in particular sits on the northern shipping lane, the lane through which laden tankers exit the Gulf. Military assets on the island can monitor, and potentially threaten, that transit lane from a position that Iranian mainland forces cannot replicate.
Iran’s subsequent development of the islands has tracked their strategic utility. Military facilities, radar installations, and at various points surface-to-air and anti-ship missile systems have been positioned on the islands, transforming what were essentially uninhabited rocks into forward operating locations. The militarization has accelerated during periods of heightened US-Iran tension, which is not coincidental — islands that provide advance warning and attack geometry for incoming naval forces are most valuable when those forces are most likely to appear.
The UAE’s pursuit of a resolution through diplomatic channels has produced no result. The issue has been raised at Arab League meetings, at GCC summits, and in bilateral discussions between Abu Dhabi and Tehran on multiple occasions. Iran’s position is that the occupation is legitimate and the matter is closed. The 2023 Saudi-Iranian normalization agreement, brokered by China, conspicuously failed to produce movement on the island dispute despite UAE hopes that improving Gulf-Iran relations might create an opening. Iran’s willingness to engage diplomatically with Saudi Arabia did not extend to territorial concessions that it views as strategic assets.
The islands complicate the UAE’s relationship with Iran in ways that have downstream effects for Gulf security architecture. Abu Dhabi cannot fully normalize with Tehran as long as Iranian forces occupy Emirati territory. At the same time, the UAE’s economic and geographic exposure to Iran — Dubai’s large Iranian business community, the UAE’s role as a trade conduit for sanctioned Iranian commerce, the maritime proximity — creates incentives for functional if uncomfortable coexistence. The UAE manages this contradiction by maintaining the formal territorial claim vigorously while conducting practical relations with Iran at whatever temperature current circumstances require.
For the strait, the islands matter because they establish Iranian presence on both the northern and southern approaches to the main shipping lanes. A country that controls observation and potential fire control positions at both the entrance and the narrowest point of the strait has leverage over transit that purely mainland-based assets could not replicate. The 1971 occupation was an act of strategic foresight. Fifty years of subsequent events have vindicated the assessment that these rocks were worth fighting over.
The UAE’s flag does not fly over them. The ships that pass beneath them carry oil that funds the UAE economy. The gap between legal claim and physical control is what geopolitical disputes look like when they are unresolved and both parties have decided that resolution costs more than perpetuation.