Abu Musa, island (2010 est. pop. 1,868), c. 4.6 sq mi (12 sq km), E Persian Gulf, disputed between Iran, who occupies it, and the United Arab Emirates. Strategically located near the entrance of the Strait of Hormuz (through which much of the world's oil supply is shipped), Abu Musa was under British control for most of the 20th cent. until 1971, when it was stipulated that Sharjah, a shiekdom that is now part of the United Arab Emirates, would control it. That same year, however, Iran, which had long claimed Abu Musa, seized it (along with Greater and Lesser Tunb. A 1971 agreement granted shared sovereignty over Abu Musa to Iran and Sharjah, but Iran maintained significant control over the island. In 1992 Iran asserted full control over Abu Musa.