Unlike the U.S., British aid to the Afghan resistance began before the Soviet invasion was actually launched, working with chosen Afghani forces during the Afghan government's close ties to the Soviet Union in the late seventies. Within three weeks of the invasion this was stepped up - cabinet secretary, Sir Robert Armstrong sent a note to Prime Minister Margaret Thatcher, Secretary of State Peter Carrington and "C", the head of MI6 arguing the case for military aid to "encourage and support resistance". Support was approved by the British government who then authorised MI6 to conduct operations in the first year of the Soviet occupation, coordinated by MI6 officers in Islamabad in liaison with the CIA and the ISI.