The long Iran–Iraq War had ended in August 1988. Iraq owed a great amount of money to Saudi Arabia and had difficulty paying it back. Saddam Hussein declared the neighboring country of Kuwait to be siphoning Iraqi crude oil from across the border, and on August 2nd, 1990 the Iraqi invasion of Kuwait started. On January 17, 1991 the US began the Persian Gulf War with a massive US led air offensive known as Operation Desert Storm.