Throughout the war of independence, the three rival nationalist movements were severely hampered by political and military factionalism, as well as their inability to unite guerrilla efforts against the Portuguese. Between 1961 and 1975 the MPLA, UNITA, and the FNLA competed for influence in the Angolan population and the international community. The Soviet Union and Cuba became especially sympathetic towards the MPLA and supplied that party with arms, ammunition, funding, and training. They also backed UNITA militants until it became clear that the latter was at irreconcilable odds with the MPLA.