The Gulf War was a 1990–1991 armed campaign waged by a 39-country military coalition in response to the Iraqi invasion of Kuwait. Spearheaded by the United States, the coalition's efforts against Iraq were carried out in two key phases: Operation Desert Shield, which marked the military buildup from August 1990 to January 1991; and Operation Desert Storm, which began with the aerial bombing campaign against Iraq on 17 January 1991 and came to a close with the American-led Liberation of Kuwait on 28 February 1991.

On 2 August 1990, Iraq invaded neighbouring Kuwait, and had fully occupied the country within two days. Initially, Iraq ran the occupied territory under a puppet government known as the "Republic of Kuwait" before proceeding with an outright annexation in which Kuwaiti sovereign territory was split, with the "Saddamiyat al-Mitla' District" being carved out of the country's northern portion and the "Kuwait Governorate" covering the rest. Varying speculations have been made regarding the true intents behind the Iraqi invasion, most notably including Iraq's inability to repay the debt of more than US$14 billion that it had borrowed from Kuwait to finance its military efforts during the Iran–Iraq War. Kuwait's demands for repayment were coupled with its surge in petroleum production levels, which kept revenues down for Iraq and further weakened its economic prospects; throughout much of the 1980s, Kuwait's oil production was above its mandatory quota under OPEC, which kept international oil prices down. Iraq interpreted the Kuwaiti refusal to decrease oil production as an act of aggression towards the Iraqi economy, leading up to the hostilities. The invasion of Kuwait was immediately met with international condemnation, including in Resolution 660 by the United Nations Security Council (UNSC), which unanimously imposed economic sanctions against Iraq in Resolution 661. British prime minister Margaret Thatcher and American president George H. W. Bush deployed troops and equipment into Saudi Arabia and openly urged other countries to send their own forces to the scene. In response to the joint call, an array of countries joined the American-led coalition, forming the largest military alliance since World War II. The bulk of the coalition's military power was from the United States, with Saudi Arabia, the United Kingdom, and Egypt as the largest lead-up contributors, in that order; Saudi Arabia and the Kuwaiti government-in-exile paid around US$32 billion of the US$60 billion cost to mobilize the coalition against Iraq.

UNSC Resolution 678 adopted on 29 November 1990 offered Iraq one final chance until 15 January 1991 to implement Resolution 660 and withdraw from Kuwait; it further empowered states after the deadline to use "all necessary means" to force Iraq out of Kuwait. Initial efforts to dislodge the Iraqi presence in Kuwait began with an aerial and naval bombardment on 17 January 1991, which continued for five weeks. During this time, as the Iraqi military found itself unable to ward off the coalition's attacks, Iraq began to fire missiles at Israel. While the coalition itself did not include Israel, the Iraqi leadership had launched the campaign under the expectation that the missile barrage would provoke an independent Israeli military response, and hoped that such a response would prompt the coalition's Muslim-majority countries to withdraw (see Arab–Israeli conflict). However, the jeopardization attempt was ultimately unsuccessful as Israel did not respond to any Iraqi attacks, and Iraq continued to remain at odds with most Muslim-majority countries. Iraqi missile barrages aimed at coalition targets stationed in Saudi Arabia were also largely unsuccessful, and on 24 February 1991, the coalition launched a major ground assault into Iraqi-occupied Kuwait. The offensive was a decisive victory for American-led coalition forces, who liberated Kuwait and promptly began to advance past the Iraq–Kuwait border into Iraqi territory. A hundred hours after the beginning of the ground campaign, the coalition ceased its advance into Iraq and declared a ceasefire. Aerial and ground combat was confined to Iraq, Kuwait, and areas straddling the Iraq–Saudi Arabia border.

The conflict marked the introduction of live news broadcasts from the front lines of the battle, principally by the American network CNN. It has also earned the nickname Video Game War, after the daily broadcast of images from cameras onboard American bombers during Operation Desert Storm. The Gulf War has gained notoriety for including three of the largest tank battles in American military history.