We already know that but we are living though the most fantastic and amaizing of all times, at least when it comes to informations.
Here is a very interesting websites that all of us might find useful in their thinking.
Here is the link on US versus Sino-Soviet relations
http://www.gwu.edu/~nsarchiv/NSAEBB/NSAEBB49/#docs
Here is the more general link to interesting documents
http://www.gwu.edu/~nsarchiv/NSAEBB/