ABSTRACT
Since 2001, the United States (US) has deployed more than 2 million troops to Afghanistan and Iraq for Operation Enduring Freedom and Operation Iraqi Freedom (OEF/OIF), often for more than one tour of duty (Tan, 2009). These major international conflicts were the first since the Vietnam War that required a great number of troops on the ground. About 50 nations have contributed troops to both conflict areas, but the majority of those deployed at any one time have been from the US. For example, in 2009, 90,000 of the 130,000 troops deployed in Afghanistan were from the US with the next largest contingents from the United Kingdom (9,500) and Germany (4,818) (ISAF, 2012).
