on skin colour was outlawed, some Portuguese commanders such as General António de Spínola began a process of "Africanization" of Portuguese forces fighting in Africa. In Portuguese Guinea, this included a large increase in African recruitment along with the establishment of all-black military formations such as the Black Militias (Milícias negras) commanded by Major Carlos Fabião and the African Commando Battalion (Batalhão de Comandos Africanos) commanded by General Almeida Bruno. While sub-Saharan African soldiers constituted a mere 18% of the total number of troops fighting in Portugal's African territories in 1961, this percentage rose dramatically over the next 13 years, with black soldiers constituting over 50% of all government forces fighting in Africa by April 1974. Coelho noted that perceptions of African soldiers varied a good deal among senior Portuguese commanders during the conflict in Angola, Guinea, and Mozambique. General Francisco da Costa Gomes, perhaps the most successful counterinsurgency commander, sought good relations with local civilians, and employed African units within the framework of an organized counterinsurgency plan. General António de Spínola, by contrast, appealed for a more political and psycho-social use of African soldiers. On the other hand, General Kaúlza de Arriaga, the most conservative of the three, appears to have doubted the reliability of African forces outside his strict control, while continuing to view African soldiers as inferior to Portuguese troops.Kaúlza de Arriaga (General), Lições de estratégia de curso de altos comandos – 1966/67 (Lessons Of Strategy in the Course of High Command – 1966/67), Vol. 12 (1971): As late as 1971, Kaúlza argued that the Portuguese government should tailor the social and political status progress of black Africans in Angola and Mozambique to the growth of the white settler population, while concluding, "blacks are not highly intelligent, on the contrary, of all peoples of the world they are the least intelligent." As the war progressed, Portugal rapidly increased its mobilized forces. Under the Salazar regime, a military draft required all males to serve three years of obligatory military service; many of those called up to active military duty were deployed to combat zones in Portugal's African overseas provinces. The national service period was increased to four years in 1967, and virtually all conscripts faced a mandatory two-year tour of service in Africa. The existence of the draft and likelihood of combat in African counterinsurgency operations over time resulted in a sharp increase in emigration by Portuguese men