The Gulf War was not formally declared a war. Instead, it was referred to as a "liberation campaign" or "Operation Desert Storm" by the United States and its allies. The conflict began when Iraqi forces invaded and annexed Kuwait in August 1990. In response, the United Nations Security Council passed a series of resolutions condemning the invasion and demanding Iraq's withdrawal. When Iraq failed to comply, the United States and a coalition of international forces launched a military campaign to expel Iraqi forces from Kuwait. The war lasted from January to February 1991 and resulted in a decisive victory for the coalition forces.