Political activism was basic to the Viet Minh, and subsequently the Viet Cong. During the French occupation, when French forces were too strong for open warfare the Viet Minh engaged in political work to lay the basis for subsequent military action. This included slogans, discussion of the work of Marx, Lenin etc, 'self-criticism' and political trials of captured enemy officials. These all had a very strong ideological bent.

This underpinning remained part of the communist armies' culture.

There is evidence that Viet Minh soldiers at Dien Bien Phu were refusing to leave their trenches to attack French positions, but this was more a military than a political issue.

Communism appealed strongly to peasant societies where capitalism seemed to offer only protection of the class system, and more of the same difficult life.

There is a book called Portrait of the Enemy that provides good insights from the Viet Cong side of the war.