The document summarizes key events and issues during the Cold War era. It describes how tensions arose between the US and Soviet Union following WWII over the development of the atomic bomb. The Cold War led to divisions in Europe and Asia, with some nations falling under communist rule. In Korea, the North invaded the South in 1950, leading to war between the two sides aided by China and the US respectively. The conflict ended in a stalemate along the original border. During this time, fears over communism grew in the US, resulting in investigations into perceived communist influences in Hollywood and fears stoked by Senator McCarthy.