Why did the United States enter the Persian Gulf War?

Why this is the answer

The Persian Gulf War began on August 2, 1990, when Iraq invaded its neighbor Kuwait, putting the Iraqi army close to Saudi Arabia and its oil. The United States and many other countries wanted Iraq out of Kuwait and out of reach of other nearby countries. In January 1991 the United States led an international coalition, authorized by the United Nations, against the Iraqi army, and within a month the coalition had driven it out of Kuwait. So the United States entered the war to force the Iraqi military from Kuwait. Memory hook: Iraq took Kuwait, the coalition took it back.