In the fall of 2002 and winter of 2003, a steady drumbeat of rhetoric and accusations from the Bush administration were leading the United States into war against Iraq.
Saddam Hussein had weapons of mass destruction he was planning to use against us. Hussein had worked with al Qaeda to carry out the 9/11 attacks. We could replace a brutal dictatorship with a democracy that would become a model for the Middle East. And so on.
After the invasion and 8½ years of war, all were proven false. Iraq did not have any WMDs, there was no connection with al Qaeda, and Iraq continues to be wracked with sectarian violence.