Agent networks that remain dormant in strategic locations until they are occupied by enemy forces. The system anticipates being “rolled over” by an enemy and obviates the need to conduct dangerous infiltration missions to insert agents into hostile territory. The virtue of a stay-behind organization is that is allows a network to make the necessary preparations for cover and clandestine communications at leisure, and thereby reduce the chances of detection.
During World War II, the technique was employed extensively by the Axis, and virtually every significant military withdrawal was accompanied by the establishment of a German stay-behind organization. During the Cold War, NATO created extensive stay-behind organizations in West Germany and Norway, considered the two vulnerable flanks to a surprise Warsaw Pact attack; more controversially, it also sponsored embryonic resistance networks in neutral Austria, Sweden, Finland, and Switzerland. Each operated independently and concealed its existence under code names, the best known being the GLADIO network in Italy, P-26 in Switzerland, and Stella Polaris in Finland.