The Legacy of the Iraq War: Unfinished Business and Self-Serving Actions.

Two decades after the U.S. invasion of Iraq, experts reflect on the lessons learned. The war was costlier and more chaotic than anticipated, and the U.S. made planning assumptions that didn't pan out. The decision to disband the Iraqi army left 400,000 combat-trained men with no income, fueling the insurgency and spawning ISIS. The invasion also created a vacuum of power that Iran filled, and the Islamic State exploited sectarian tensions. The war ultimately failed to uncover any weapons of mass destruction and cost an estimated $2 trillion.