The latest surge in tensions between the United States and Iran — once again centered on the Strait of Hormuz — has refocused global attention on three small islands in the Persian Gulf. Though tiny in size, Abu Musa, Greater Tunb, and Lesser Tunb sit at the strategic entrance to the Strait of Hormuz, one of the world’s most critical maritime chokepoints. An estimated 20% of global oil trade and a major share of liquefied natural gas (LNG) exports pass through this narrow waterway — placing these islands at the heart of the geopolitical rivalry between Washington and Tehran.
Geographic Leverage, Disproportionate Influence
Collectively, the three islands cover less than 25 square kilometers. Yet their location along the deep-water shipping lane used by massive oil tankers grants them outsized geopolitical weight. Abu Musa serves as Iran’s most important military base in the region. It hosts units of the Islamic Revolutionary Guard Corps (IRGC), missile systems, air defense batteries, and a fleet of fast-attack craft deployed for patrols and operations in the Strait.
Similar military infrastructure operates on Greater Tunb, while Lesser Tunb hosts exclusively military facilities. Together, they form an integrated defensive network enabling Tehran to monitor commercial and naval vessel movements — and, in times of crisis, threaten freedom of navigation through the Strait.
A 55-Year Sovereignty Dispute
The dispute over control of the islands dates back to November 30, 1971, when then-Iranian Shah Mohammad Reza Pahlavi launched a military operation to seize all three islands just two days before the formal establishment of the United Arab Emirates (UAE). Since then, Iran has maintained full de facto control. However, the UAE continues to claim sovereignty over the islands and seeks resolution through international legal channels.
This remains one of the longest-running territorial disputes in the Gulf — a persistent source of friction between Iran and its Arab neighbors.
From the Tanker War to Today
The islands’ military significance became starkly evident during the 1980s ‘Tanker War’, part of the broader Iran-Iraq conflict. Iran used its bases on Abu Musa and Greater Tunb to launch attacks on merchant vessels, lay naval mines, and conduct harassment operations against international shipping. In response, the U.S. began escorting oil tankers through the Gulf — triggering a series of naval confrontations that underscored how easily maritime traffic through the Strait could be disrupted.