In 1964 the MPLA reorganized and increased its efforts to reinforce its units fighting in the Dembos areas. The improved efficiency of the movement's political and military operations attracted support from other African countries, the OAU, and several non-African countries, all of which had previously scorned the MPLA because of its internal problems.

The growing military success of the MPLA in the mid-1960s was largely the product of support from the governments of Tanzania and Zambia, which permitted the organization to open offices in their capitals. More important, Tanzania and Zambia allowed the transport of Chinese and Soviet weapons across their territories to the Angolan border. Because of the influx of weapons, in 1965 the MPLA was able to open a military front in eastern Angola, from which it launched a major offensive the following year. By this time, the MPLA had become a greater threat to Portugal's colonial rule than the FNLA.

In June 1966, the MPLA supported an unsuccessful coup against President Marien Ngouabi of Congo, whereupon activities of all guerrilla groups in Brazzaville were curtailed. After the MPLA moved its headquarters to Lusaka, Zambia, in 1968, it conducted intensive guerrilla warfare in the Angolan provinces of Moxico and Cuando Cubango.

Beginning in 1969, attacks in Lunda and Bié provinces forced the Portuguese to resettle many inhabitants of these areas in fortified villages. Wherever MPLA guerrillas were in control, they created new political structures, mainly village action committees. Politically indoctrinated MPLA guerrillas, some of whom had received military training in Eastern Europe, ranged all over eastern Angola. By 1968 the MPLA was able to hold regional party conferences inside the country.

The MPLA had a political advantage over the FNLA because of the links of MPLA leaders to the international ideological left. Its multiracial, Marxist-Leninist, and nationalist (versus ethnic or regional) views appealed to liberals in Europe and North America. Because of his radical orientation, however, Neto failed to get help from the United States. During the mid-1960s, the MPLA's ties to the communist world intensified as MPLA military cadres traveled to the Soviet Union, Czechoslovakia, and Bulgaria. Beginning in 1965, the MPLA began to receive training from Cuban forces.

Data as of February 1989