The whole document is phrased much like the Declaration of Independence of the United States, and the way the Vietnamese presented their struggle against the French was as similar to how Americans had presented their struggle against Britain. They probably knew Americans at this time didn't like communists and were trying to present it in a way Americans might be able to understand (perhaps to deter Americans from aiding the French in taking back Vietnam). Yet, despite the similarities and the US agreeing nations should be self-governing, the US government just completely ignores the will of the Vietnamese people and goes to war against them anyway. They saw communism as such a threat that they couldn't see the hypocrisy.