Why did the United States enter the Persian Gulf War?

Why this is the answer

USCIS accepts one answer here: the United States entered the Persian Gulf War to force the Iraqi military from Kuwait. On August 2, 1990, Iraq invaded and occupied Kuwait, an attack Congress later described as made without provocation. The invasion also put the Iraqi army closer to Saudi Arabia and its oil reserves, which supplied much of the world. The international community demanded that Iraq withdraw immediately and without conditions. In Resolution 678 the United Nations Security Council authorized member states to use all necessary means after January 15, 1991, if Iraq had not complied. Congress then voted to authorize the President to use American armed forces under that UN resolution, and the measure became Public Law 102-1 on January 14, 1991, one day before the deadline. The fighting was fast. In January 1991 the United States led an international coalition into battle against the Iraqi army, and within a month the coalition had driven the Iraqis from Kuwait. A cease-fire followed on February 28, 1991. It is one of the five wars the United States fought in the 1900s. The aim was to get the Iraqi military out of Kuwait and keep it from invading other nearby countries. The distinction matters because the United States went to war with Iraq again in March 2003, after the September 11 attacks. That later war belongs to a different question on the list, where "War in Iraq" is one of the military conflicts after the September 11, 2001 attacks. An easy way to keep them apart is to pair each year with its purpose: in 1991, forcing the Iraqi military from Kuwait; in 2003, as the President announced that March, military operations to disarm Iraq. Two of the wrong answers come from other questions. USCIS gives "to stop the spread of communism" as the reason the United States entered both the Korean War and the Vietnam War, and the United States entered World War II after Japan attacked Pearl Harbor. Neither fits here, so the word to pair with "Persian Gulf" is Kuwait.