In the 1960s, the Soviet Union sought to close the gap between conventional arms and the specialized requirements of clandestine warfare.Reconnaissance teams, Spetsnaz elements of the Soviet Army, and KGB operatives were expected to operate behind enemy lines or when silent work was required during any operation, and this placed a premium on weapons that were not only reliable and compact but also quiet.Out of that requirement came one of the first mass-produced Soviet handguns purpose-built for suppressed, covert work: the PB (GRAU index 6P9).