Within days of the Alvor Agreement, the Central Intelligence Agency launched its own programme, Operation IA Feature, to arm the FNLA, with the stated objective of "prevent an easy victory by Soviet-backed forces in Angola". The United States was searching for regional allies to take part in Operation IA Feature and perceived South Africa as the "ideal solution" in defeating the pro-Soviet MPLA. With tacit American encouragement, the FNLA and UNITA began massing large numbers of troops in northern and southern Angola, respectively, in an attempt to gain tactical superiority. The transitional government installed by the Alvor Agreement disintegrated and the MPLA requested support from its communist allies. Between February and April 1975 the MPLA's armed wing, the People's Armed Forces of Liberation of Angola (FAPLA), received shipments of Soviet arms, mostly channelled through Cuba or the People's Republic of the Congo. At the end of May FAPLA personnel were being instructed in their use by a contingent of about 200 Cuban military advisers. Over the next two months they proceeded to inflict a series of crippling defeats on the FNLA and UNITA, which were driven out of the Angolan capital, Luanda.