How would the world be different today if the US had stayed out of the Vietnam War?

I know very little about this war and wouldn't mind maybe reading a book about it. But I don't know where to start. I'd love something that added context without pushing a political agenda. So I don't want an anti-communist book, or really even an explicitly ani-capitalist one. I'd like to think I could understand the power vectors and their impact on ordinary people. This is hard to do!