The MBT-70 was a 1960s joint German -U.S.-project to develop a new main battle tank using a number of advanced design features. It used a kneeling suspension, housed the entire crew in the turret, and the American version incorporated a gun-fired missile. By the late 1960s the project was well over budget and the Germans withdrew from the effort, developing their Leopard 2 instead. Development continued in the US, but the per-unit cost had risen five times, and in 1971 Congress overrode the Army's objections and the MBT-70's funding was redirected to create the more successful M1 Abrams.