The Gulf War , in which A , B and D squadrons deployed , was the largest SAS mobilisation since the Second World War , also notable for the failure of the Bravo Two Zero mission . In Sierra Leone it took part in Operation Barras , a hostage rescue operation , to extract members of the Royal Irish Regiment . Following the September 11 attacks on the United States by al-Qaeda in 2001 , 2 squadrons of 22 SAS , reinforced by members of both the territorial SAS units deployed to Afghanistan as part of the Coalition invasion at the start of the War in Afghanistan ( 2001 – present ) , to dismantle and destroy al-Qaeda and to deny it a safe base of operations in Afghanistan by removing the Taliban from power in the War on Terror . The Regiment carried out Operation Trent – the largest operation in its history , which included its first wartime HALO parachute jump . Following the invasion , the Regiment continued to operate in Afghanistan against the Taliban and other insurgents until 2006 , where its deployment Iraq became its focus of operations until 2009 , when the SAS redeployed to Afghanistan
September 11 attacks
September 11 attacks
Special Air Service