U.S. Marine Corps Sgt. Estevan Perez, a diesel mechanic with 3rd Battalion, 3rd Marines, works hard to fix a broken steering gear one of the High-Mobility Multipurpose Wheeled Vehicles (HMMWV) assigned to Jalalabad, Afghanistan, on Dec. 22, 2004. These Marines are conducting security and stabilization operations in support of Operation Enduring Freedom. (U.S. Marine Corps Photo by Cpl. James Yarboro)