The main cause of the internal conflict in Vietnam from the 1950s to the 1970s was the struggle between communist and non-communist forces, primarily represented by the North and South Vietnamese governments. The North, supported by the USSR and China, aimed to unify Vietnam under communism, while the South, backed by the United States, sought to maintain a capitalist regime. The conflict was also fueled by deep-rooted social, economic, and political issues, leading to significant human suffering and international involvement. Ultimately, it became a focal point of the Cold War, reflecting wider ideological battles.