into PAIGC-controlled territory. At this time Portuguese forces also adopted unorthodox means of countering the insurgents, including attacks on the political structure of the nationalist movement. Nonetheless, the PAIGC continued to increase its strength, and began to heavily press Portuguese defense forces. In 1970 the Portuguese Air Force (FAP) began to use weapons similar to those the US was using in the Vietnam War: napalm and defoliants in order to find the insurgents or at least deny them the cover and concealment needed for rebel ambushes. In general, the PAIGC in Guinea was the best armed, trained, and led of all the guerrilla movements. After 1968 PAIGC forces were increasingly supplied with modern Soviet weapons and equipment, most notably SA-7 rocket launchers, radar-controlled AA cannon, and even jet aircraft in the form of several Ilyushin Il-14 bombers. These weapons effectively undermined Portuguese air superiority, preventing the destruction by air of PAIGC encampments in territory it controlled. By 1970 the PAIGC even had candidates training in the Soviet Union, learning to fly MIGs and to operate Soviet-supplied amphibious assault crafts and APCs. Considerable support to the PAIGC from Yugoslavia began in after 1968, in the forms military equipment, tactical, technical, and political training for PAIGC leadership, and medical aid. Yugoslavia also built a well-equipped hospital in Boké for PAIGC fighters, which was staffed by both Yugoslav and Cuban doctors, which was the flagship of the PAIGC health services. Invasion of Guinea: November 1970 In late November 1970, Portugal launched Operation Green Sea, an amphibious attack on Guinea-Conakry designed to capture the PAIGC leadership, including Cabral, and to topple Guinean President Ahmed Sékou Touré, ideally to be replaced by a leader more willing to cooperate with the Portuguese and to obstruct PAIGC's supply lines. Chabal views the operation as "ill-timed and ill-prepared" and as "desperate": the Portuguese operatives were dispersed and expelled from Conakry, and, having revivified Third World political support for PAIGC, the misadventure strained Portuguese relations with other Western countries. The United Nations (UN) Security Council unanimously condemned the operation in Resolution 290, and the following year passed Resolution 291 condemning other cross-border incursions by Portugal into Guinea. Over the next two years, Portugal failed to make military advances or to forestall the consolidation of PAIGC's advances. By the beginning of 1972, although territorial boundaries remained blurry, most of the country belonged to one of PAIGC's liberated zones; by the