Brown University's Costs of War project released a study last week which states that it is the first analysis to comprehensively measure the number of people forced to flee their homes as a result wars involving the United States since 2001. It states that 37 million people have been displaced by America's Global War On Terror and that estimate is likely conservative with the true figure possibly as high as 59 million. The study points out that it focuses on conflicts where the U.S. government bears a clear responsibility for initiating/escating armed combat or where it has been a significant participant via other means such as battlefield advising, drone strikes, arms sales or other means. It does not suggest that the U.S. alone is solely responsible for displacement as causation involves multiple and complex factors.
Out of the 37 million people thought to have been displaced across eight countries since the U.S. intervened military in Afghanistan in 2001, 29 million were displaced internally while eight million were displaced beyond their borders. At least 25.3 million are now thought to have returned home, though that does not mean they have experienced an end to their trauma nor a secure life in their original homes. With 9.2 million people displaced since the U.S. invaded in 2003, Iraq suffered the worst impact out of all countries in the analysis. Neighboring Syria has just over 7 million displaced with the U.S. becoming military involved in the country in September 2014. Brown University estimated that 5.3 million people were forced from their homes in Afghanistan, the longest war in U.S. history.
U.S. involvement in other conflicts has been low key, particularly in the Philippines where troops have served in an advisory capacity as the government battles an insurgency in the southern islands of Minanao. The study estimates that 1.7 million people have been displaced in the conflict, virtually all of them internally. Yemen is another example of a war where U.S. participation has not been immediately obvious. Washington has supplied Saudi Arabia and its allies with modern hardware that has fueled the conflict while U.S. special forces have directly carried out raids and drones have conducted targeted assassinations. So far, 4.4 million people have been displaced in Yemen.
The study attempts to put the total conservative estimate of 37 million into some form of perspective by stating that it is equivalent to removing nearly all the residents of California or all of the people in Texas and Virginia combined. Historically, that figure is higher than the number displaced by war or any disaster since the start of the 20th century with the exception of the World War II.