The Gulf War (August 2, 1990 – February 28, 1991), codenamed Operation Desert Shield (August 2, 1990 – 17 January 17, 1991) for operations leading to the buildup of troops and defense of Saudi Arabia and Operation Desert Storm ( January 17, 1991 –February 28, 1991) in its combat phase, was a war waged by coalition forces from 35 nations led by the United States against Iraq in response to Iraq's invasion and annexation of Kuwait arising from oil pricing and production disputes. The war is also known under other names, such as the Persian Gulf War, First Gulf War, Gulf War I, Kuwait War, First Iraq War or Iraq War, before the term "Iraq War" became identified instead with the post-2003 Iraq War.