Why did the Gulf War happen?

The Gulf War occurred after Iraq invaded its neighbor Kuwait in 1990. Iraq resisted U.N. demands to leave Kuwait, so U.S. and coalition forces attacked to remove them and to protect Saudi Arabia. The ground campaign lasted for approximately 100 hours and resulted in resounding defeat for Iraqi forces.

In 2003, the United States claimed that Iraq was manufacturing weapons of mass destruction and initiated an invasion of Iraq. This war resulted in the removal of Saddam Hussein from power, his execution and a lengthy occupation of the country. Investigations revealed no substantial evidence of an active weapons of mass destruction program, leading many to question the original motive for entering the war.