The West was concerned when China became Communist in 1949 because they were worried that Communism may begin to spread
As a result of the Treaty of Friendship, the USSR and China agreed to support each other and formed an alliance
UN troops became involved in the Korean War because South Korea asked the UN for help when North Korea invaded in June1950, and the Americans saw their chance to intervene
The Korean War caused divisions between the superpowers to become more entrenched
China becoming Communist in 1949
The balance of power had shifted in favour of the USSR, which encouraged the USA to expand its containment policy to Asia
The outbreak of the Korean War in 1950
American troops were engaged in active battle against Communist forces, especially after China entered the war in October1950, which meant that divisions became more firmly entrenched