While the U.S. Army is doing most of the work in Iraq, it has managed to get the air force and navy to contribute nearly 4,000 troops for combat support jobs. The air force has 1,500 airmen running convoys throughout Iraq and another thousand air force security personnel guarding prisoners. The navy helps out with logistics, construction and other support tasks. The navy is also increasing the size of it's "brown water navy" force, to help provide combat forces along the coast and on the rivers of Iraq.
The air force and navy also have over 10,000 troops performing more traditional tasks, like running and guarding air bases and port facilities, as well as providing air support and air transport.