Starting in 1969 President Richard Nixon started the process of "Vietnamization", pulling out American forces and rendering the ARVN capable of fighting an effective war against the People's Army of Vietnam (PAVN) and VC. Slowly, the ARVN began to expand from its counter-insurgency role to become the primary ground defense against the PAVN/VC. From 1969 to 1971 there were about 22,000 ARVN combat deaths per year. Starting in 1968, South Vietnam began calling up every available man for service in the ARVN, reaching a strength of one million soldiers by 1972. In 1970 they performed well in the Cambodian Incursion and were executing three times as many operations as they had during the American-led war period. However, the ARVN equipment continued to be of lower standards than their American and other allies, even as the U.S. tried to upgrade ARVN technology. The officer corps was still the biggest problem. Leaders were too often inept, being poorly trained, corrupt and lacking morale. Still, Sir Robert Thompson, a British military officer widely regarded as the worlds foremost expert in counterinsurgency warfare during the Vietnam War, thought that by 1972, the ARVN had developed into one of the best fighting forces in the world, comparing them favorably with the Israeli Defence Forces. Forced to carry the burden left by the Americans, the ARVN actually started to perform rather well, though with continued American air support.