Complex sentence: It was in theory a communist resistance movement meant to fight alongside the Viet Minh against French colonialism during the first Indochina War, but it never really fought much of anyone and was organized as a reserve organization of the Viet Minh.
Split into simpler sentences: It was in theory a communist resistance movement meant to fight alongside the Viet Minh against French colonialism during the first Indochina War. But it never really fought much of anyone and was organized as a reserve organization of the Viet Minh.