FDR had stated he was against the re-acquisition of Indochina by the French after WWII. Unfortunately he didn’t make it that long. Truman ignored Ho Chi Minh’s plea for help and backed the French.
Ho Chi Minh had come to power in Vietnam with the assistance of the OSS in the wake of the Japanese surrender in September 1945. He had not yet been tarred with the Communist label– that came later for political reasons. Truman sacrificed Ho in order to keep the French solidly in the Western bloc against the Russians at the end of the war…the rest of course was tragedy….