"Responding to recent setbacks in Iraq and Syria in the fight against the Islamic State organization (IS, aka ISIL/ISIS/Daesh), on June 10, 2015, President Obama authorized the deployment of an additional 450 troops to train, advise, and assist the Iraqi Security Forces. These U.S. forces are to join the 3,100 already in theater, which would bring the total number of U.S. forces in Iraq up to approximately 3,550. Approximately half of those additional forces would advise the 8th Iraqi Division on the use of its ground forces and help build connections between the government in Baghdad and local Sunni tribes in Anbar province. The other half are to perform logistic and force protection functions. Reflecting the shift in the campaign's center of gravity away from Mosul in northern Iraq, new troops are to be based in Anbar Province at Taqaddum, an Iraqi air base situated between Ramadi and Fallujah. This would be the fifth training site established in the counter-IS campaign; U.S. trainers are also operating out of Al-Asad, Besmaya, Irbil, and Taji. The deployments appear to be evolving into a 'lily-pad' basing footprint across the country. As of May 21, 2015, the United States spent upwards of $2.57 billion on military operations in Iraq and Syria since August 2014; the average daily cost of counter-IS operations in both Iraq and Syria was $9.0 million."
CRS Report for Congress, R44073
Federation of American Scientists: http://www.fas.org/sgp/crs/index.html