Underground movements that fought against Nazi Germany and Japan during World War II. Their activities involved publishing underground newspapers, helping Jews and prisoners-of-war to escape, conveying intelligence by secret radios, as well as committing acts of sabotage. In occupied Europe there were often deep divisions between communist and non-communist organizations, notably in France, where the Maquis was active, as well as in Belgium, Yugoslavia, and Greece. Communist parties had at first remained passive, but following the German invasion of the Soviet Union (June 1941), they formed or joined underground groups. Dutch, Danish, and Norwegian resistance remained unified and worked closely with London, where in 1940 the British Special Operations Executive (SOE) was set up to coordinate all subversive activity, both in Europe and the Far East, and to supply arms and equipment by secret air-drops. In the Far East clandestine operations were carried out through British and US intelligence organizations. Much of their effort was devoted to intelligence gathering, psychological warfare, and prisoner-of-war recovery, while the actual sabotaging of selected installations and communication lines was conducted by native-born, nationalist, and often communist-inspired guerrillas.