3 takeaways 20 years after the invasion of Iraq

Two decades ago, U.S. air and ground forces invaded Iraq in what then-President George W. Bush said was an effort to disarm the country, free its people and "defend the world from grave danger."

In the late-night Oval Office address on March 19, 2003, Bush did not mention his administration's assertion that Iraqi dictator Saddam Hussein possessed weapons of mass destruction. That argument — which turned out to be based on thin or otherwise faulty intelligence — had been laid out weeks before by Secretary of State Colin Powell at a U.N. Security Council meeting.

Bush described the massive airstrikes on Iraq as the "opening stages of what will be a broad and concerted campaign" and pledged that "we will accept no outcome but victory."

However, Bush's caveat that the campaign "could be longer and more difficult than some, and at least 270,000 Iraqis, mostly civilians, were killed. While the invasion succeeded in toppling Saddam, it ultimately failed to uncover any secret stash of weapons of mass destruction. Although estimates vary, a puts the cost of the combat phase of the war at around $2 trillion.