British troops in Greece supported Monarchists who were against Communism.

A Civil War developed.

Britain couldn't afford to stay in Greece so started to withdraw.

Truman paid for British troops to stay in Greece and support the Monarchists.

Truman was worried that Stalin would start expanding Communism West.

The Monarchists got control but only a weak government.

This intervention in Greece was an example of the Truman Doctrine.