The United States and the United Nations gave several public justifications for involvement in the conflict, the most prominent being the Iraqi violation of Kuwaiti territorial integrity. In addition, the United States moved to support its ally Saudi Arabia, whose importance in the region, and as a key supplier of oil, made it of considerable geopolitical importance. Shortly after the Iraqi invasion, Secretary of Defense Dick Cheney made the first of several visits to Saudi Arabia where King Fahd requested US military assistance. During a speech in a special joint session of the U.S. Congress given on 11 September 1990, U.S. President George H.W. Bush summed up the reasons with the following remarks: "Within three days, 120,000 Iraqi troops with 850 tanks had poured into Kuwait and moved south to threaten Saudi Arabia. It was then that I decided to act to check that aggression."

The Pentagon claimed that satellite photos showing a buildup of Iraqi forces along the border were the source of this information, but this was later shown to be false. A reporter for the Saint Petersburg Times acquired commercial satellite images made at the time in question, which showed nothing but empty desert.

Other justifications for foreign involvement included Iraq’s history of human rights abuses under President Saddam. Iraq was also known to possess biological weapons and chemical weapons, which Saddam had used against Iranian troops during the Iran–Iraq War and against his own country's Kurdish population in the Al-Anfal Campaign. Iraq was also known to have a nuclear weapons program.

Although there were human rights abuses committed in Kuwait by the invading Iraqi military, the ones best known in the U.S. were inventions of the public relations firm hired by the government of Kuwait to influence U.S. opinion in favor of military intervention. Shortly after Iraq’s invasion of Kuwait, the organisation Citizens for a Free Kuwait was formed in the U.S. It hired the public relations firm Hill & Knowlton for about $11 million, paid by the Kuwaiti government.

Among many other means of influencing U.S. opinion (distributing books on Iraqi atrocities to U.S. soldiers deployed in the region, 'Free Kuwait' T-shirts and speakers to college campuses, and dozens of video news releases to television stations), the firm arranged for an appearance before a group of members of the U.S. Congress in which a woman identifying herself as a nurse working in the Kuwait City hospital described Iraqi soldiers pulling babies out of incubators and letting them die on the floor.

The story was an influence in tipping both the public and Congress towards a war with Iraq: six Congressmen said the testimony was enough for them to support military action against Iraq and seven Senators referenced the testimony in debate. The Senate supported the military actions in a 52-47 vote. A year after the war, however, this allegation was revealed to be a fabrication. The woman who had testified was found to be a member of the Kuwaiti Royal Family, in fact the daughter of the Kuwaiti ambassador to the U.S. She had not been living in Kuwait during the Iraqi invasion.

The details of the Hill & Knowlton public relations campaign, including the incubator testimony, were published in a John R. MacArthur's Second Front: Censorship and Propaganda in the Gulf War (Berkeley, CA: University of CA Press, 1992), and came to wide public attention when an Op-ed by MacArthur was published in the New York Times. This prompted a reexamination by Amnesty International, which had originally promoted an account alleging even greater numbers of babies torn from incubators than the original fake testimony. After finding no evidence to support it, the organization issued a retraction. President George H. W. Bush then repeated the incubator allegations on television.

At the same time, the Iraqi army committed several well-documented crimes during its occupation of Kuwait, such as the summary execution without trial of three brothers after which their bodies were stacked in a pile and left to decay in a public street. Iraqi troops also ransacked and looted private Kuwaiti homes, one residence was repeatedly defecated in. A resident later commented, "The whole thing was violence for the sake of violence, destruction for the sake of destruction... Imagine a surrealistic painting by Salvador Dalí".