The Cold War was between USSR and the U.S. only. Today, Vietnam and the U.S. have a relatively strong relationship. When the U.S. retreated from the Vietnam war, tensions were high as Vietnam fell to communism. However, since then, the relationship between Vietnam and America is very different.
Irony: "I've got more faith in Hitler than in anyone else. ... Elie means that Hitler has kept his promise of killing off all the Jews, while God has not kept any of his to help.
The infinitive phrase in this sentence is to speak clearly, and it is used as a subject of the sentence. What/who is essential to being understood? To speak clearly.