By the late 1950s and early 1960s, the success of revolutionary warfare techniques against conventional armies in China, Indochina, Algeria, and Cuba led the conventional armies in the developed and underdeveloped worlds to concentrate on finding military and political strategies to fight domestic revolutionary warfare. This led to an adoption of what Stepan called, in 1973, “New Professionalism.” The New Professionalism was formulated and propagated in Brazil through the Escola Superior de Guerra, which had been established in 1949. By 1963 New Professionalism had come to dominate the school, when it declared its primary mission to be preparing “civilians and the military to perform executive and advisory functions (Decreto Lei No. 53,080 December 4, 1963).” This new attitude towards professionalism did not arise out of nowhere. Though its domination of the ESG was completed by 1963, it had begun to penetrate the college much earlier than that — assisted by the United States and its policy of encouraging Latin American militaries to assume as their primary role in counter-guerrilla and counter-insurgency warfare programs, civic action and nation-building tasks.
By 1964, at the same time that the military elite were unsatisfied with the natural delay, transfers and accommodation, characteristics of the negotiation processes in democratic regimes and was also eager to impose their development project, saw a leftist revolution as a real possibility (through the paradigm of internal warfare doctrines of the new professionalism). Events like the rising strike levels, the inflation rate, embraced demands by the Left for broaden political process, land reform and the growing claims of the enlisted men were seen as "evidence" that Brazil was facing the serious possibility of a leftist internal insurgency.