This paper analyzes the theoretical and political journey that the Socialist Party of Chile, PSCh, traveled on the road of building and shaping a military dimension that included a strategic definition and the military political formation of its militants. We maintain that this approach was strongly influenced by the discussions that took place abroad, in exile, and the links that the Party began to weave with international solidarity. Thus, the Sandinista Revolution, the legitimization of the regime through the 1980 plebiscite and the beginning of popular protests in 1983, facilitated the staging of military devices within the collectivity that were linked to the upward process of opposition to the regime. This military dimension was not only the staging of certain military actions, but also included a broader conception around the military issue, as was the discussion towards the armed forces, improving security and intelligence levels within the organization. Based on the above, we can identify three moments of development of this military dimension; the socialist participation in the Sandinista Revolution, interviews and bibliography on the subject.