A new report finds at least 37 million people in eight countries have fled their homes since the start of the U.S.-led, so-called global war on terrorism in 2001. The report by the Costs of War Project at Brown University also finds more than 800,000 people have been killed since U.S. forces began fighting in Afghanistan, Iraq, Syria, Pakistan and Yemen, at a cost of $6.4 trillion to U.S. taxpayers.