The French underground

In 1940, the Philippe Petain Presidency of France was anti-communist and efficient. But a network of communist operatives led by Soviets worked to undo the efforts of the legitimate government and it was their effort that in many ways made the difference in the final defeat of France and ultimately, most of Europe to communism and its enablers.

Those communist "underground" terrorists later became known as the French Underground were hailed as "heroes" by the communists who won the war.