Designed in the 1950s, the US Marines' M50 Ontos and the US Army's M56 Scorpion were both intended to be fast, light, air-droppable tank-killers for the Cold War battlefield--an answer to the cumbersome and ineffective World War II-vintage tanks that had taken to the battlefield during the Korean War. Although they shared the aim of bringing light, mobile, and lethal antitank firepower to the infantry, the two vehicles varied wildly in design to cater for their unique mission demands. They first saw service in the Lebanon intervention of 1958 but it was in the Vietnam War that they made their name, with the M50 Ontos seeing intense combat action in the 1968 Battle of Hue.

Design and development: M56 Scorpion, The M50 Ontos -- Specifications -- Operational history: The M50 Ontos, M56 Scorpion ; Foregn service and variants: variants.