The thesis for your essay could be something along the lines of the following: The Persian Gulf War began after Iraq under Saddam Hussein invaded Kuwait in 1990 and the U.S. spearheaded a campaign called Operation Desert Storm that appeared to achieve success; however, the war left behind unresolved issues that in part led to a second war in the region in 2003.
Here is some additional background information: Accusing Kuwait of taking oil from Iraqi oilfields, Saddam Hussein invaded Kuwait in August of 1990. He fully expected that other Arab states would back his actions. However, most of the countries condemned Iraq for its actions and called on the U.S. and NATO for help. In November of 1990, the U.N. resolved to carry out action against Iraq if it did not remove its troops from Kuwait, and the first U.S. air raids began in January of 1991. Using laser-guided missiles and night-bombing technology, the U.S. air attacks quickly disposed of Iraqi opposition, and the American troops moved on to a ground war in which they rapidly rid Kuwait of Iraqi forces. While Iraq abandoned its claims on Kuwait, massive damage resulted from the war. The success of the war became more controversial when Hussein, who was left in power, began mounting attacks against Kurds and Shi'ites in his country. Frustrated by the Iraqis' failure to submit to weapons inspections and to observe no-fly zones, the U.S. under the second President Bush attacked Iraq in 2003, starting the Iraq War.