"Stay-Behind" refers to secret networks established during the Cold War, primarily in Europe, to counter potential invasions by the Soviet Union. These networks were designed to remain operational even if conventional military forces were defeated, allowing them to conduct guerrilla warfare and sabotage operations. The most notable example is the Gladio operation in Italy, which involved the creation of clandestine groups supported by NATO and local governments. These groups were intended to gather intelligence and resist occupation, but their existence has raised ethical concerns and controversies regarding accountability and the potential for misuse.