Why did american fears about the spread of communism intensify after the communist victory in chines civil war

Basically, the Soviet Union was joined by China which was a big deal since both countries were huge and powerful and this was problematic for the United States. With such two powers controlling Asia and Eastern Europe, they believed that they could easily work together in getting other parts of the world to join them too like South East Asia or Latin America.

Explanation:

uncle sam would be tossing and turning in his grave : *)

not sure might be he acquired the entire oregon territory from great britain