The September 5, 2002 report from the Glen Shaffer, (which was initially classified as secret) showed the U.S. knew about Iraq's internal expertise in building nuclear weapons but failed to mention it and bring it to light until after the war was finished. At a February 12, 2003 press conference, Rumsfeld said Iraq was engaging in the development of weapons of mass destruction weapons, biological weapons, chemical weapons and ballistic missiles.
On March 20 in 2003, the United States and a coalition of allies invaded Iraq.
President George W. Bush said two days later in his weekly radio address that the cause the coalition was pursuing was the security of the nation’s we serve and the peace of the world.
America was nervous that Iraq possessed more powerful WMD’s and believed that by Invading they would be able to take control of them, and bring them back to the US. AS well as this the US was nervous that Iraq wouldn’t be scared about having a war with them when there WMD’s had reached a stronger level.
Although Saddam never admitted to having WMDs he did hint to the Americans. The Americans didn’t like this and felt as though they had to know the whole world business, especially if the Iraq and American relationship became hostile.
9/11 had shown the world Americas vulnerability – their kryptonite as such, and America feared further attacks.