<human>:  Why did the US invade Iraq in 2003?
<bot>: The invasion of Iraq was based on the false assumption that Iraq had weapons of mass destruction. However, after the invasion, it was discovered that Iraq did not have any WMDs. The war in Iraq was also based on the false assumption that Saddam Hussein was responsible for the 9/11 attacks. After the war, it was discovered that Iraq had no ties to the 9/11 attacks.