The entire force totalled around 3,300 troops. This was a journey into the unknown for British soldiers because they were taking over from US forces. However, it soon became clear that the hope of John Reid, the defence secretary, that we would be able to leave within three years without a shot being fired was unrealistic. The main combat power was provided by 3 Battalion The Parachute Regiment supported by 1 Battalion The Royal Irish, the Apache attack helicopters of 9 Regiment Army Air Corp, Chinooks from 27 Squadron RAF, 7 Parachute Regiment Royal Horse Artillery, a battery of Desert Hawk unmanned aerial vehicles from 32 Regiment Royal Artillery and Royal Engineers from 51 Parachute Squadron. Other support roles were assumed by 13 Air Assault Regiment RLC (Royal Logistic Corps), 7 Air Assault Battalion REME (Royal Electrical and Mechanical Engineers) and 16 Air Assault Medical Regiment. Harriers from the Joint Force Harrier detachment, which had been operating from Kandahar since September 2004, provided troops with vital close air support; 34 Squadron of the RAF Regiment offered Force Protection.