Gladio (Italian, from Latin gladius, meaning sword) is a code name denoting the clandestine NATO "stay-behind" operation in Italy after World War II, intended to counter an eventual Warsaw Pact invasion of Western Europe. Although Gladio specifically refers to the Italian branch of the NATO stay-behind organisations, "Operation Gladio" is used as an informal name for all stay-behind organisations.
The role of the CIA in sponsoring Gladio and the extent of its activities during the Cold War era, and its relationship to attacks perpetrated in Italy during the years of lead and other similar clandestine operations is the subject of ongoing debate and investigation.
