What is biggest mistake the U.S. government has ever made?

I think the biggest mistake the United States (US) government has made was claiming Iraq had weapons of mass destruction to justify the invasion of Iraq in 2003. The Iraq war added over $1 trillion to the US debt. Almost 4,500 US troops died and over 32,000 suffered injuries.

The war also left devastation in Iraq and even though the US is no longer present in Iraq, the war continues for the people of Iraq. It has been reported that 2013 was the deadliest since the height of the war in 2008 because fighting between Iraq’s Shiite majority and Sunni minority continues to this day. The fighting has also now spread to Syria, Jordan and Lebanon.