On 2 August 1990 Iraq invaded its rival oil-exporting neighbour Kuwait. The invasion was widely condemned, and four days later the United Nations (UN) Security Council unanimously approved a trade embargo against Iraq. A blockade of Iraq’s access to the sea followed within weeks, as the United States assembled a large multinational task force in the Persian Gulf, while another was formed in Saudi Arabia. Australia was one of the first nations to join the coalition force. Australian forces were deployed under the auspices of the UN. Three Australian warships conducted blockade operations in the Persian Gulf. Australia also provided a supply vessel, four medical teams and a mine clearance diving team that joined a protective screen, under US operational control, around aircraft-carrier battle groups in the Gulf. The Royal Australian Navy (RAN) provided vessels for the multinational naval force, which formed an interception force in the Persian Gulf to enforce the UN sanctions. The RAN presence included two frigates and the replenishment ship HMAS Success, which, having no air defences of its own, relied on the army’s 16th Air Defence Regiment. In January 1991 the replenishment tanker HMAS Westralia left Fremantle, Western Australia, to relieve Success. Four warships, HMAS Sydney (IV), HMAS Adelaide, HMAS Brisbane, and HMAS Darwin, also served tours of duty in the Persian Gulf.