MBT-70

The MBT-70 (German: KPz 70) was a 1960s German-U.S. joint project to develop a new main battle tank, which was to be equipped with a number of advanced features. It utilized a newly developed hydropneumatic "kneeling" suspension and housed the entire crew in the large turret. The MBT-70 was armed with a 152 mm XM-150 gun/launcher, which could use conventional ammunition and the Shillelagh missile for long range combat.

In 1969 the project was well over budget and the Germans withdrew from the effort, developing a new main battle tank on their own instead (the Leopard 2). In the US the development continued for a short time, until in 1971 the Congress cancelled the program. The MBT-70 is the "grandfather" of the Leopard 2 and the M1 Abrams, the current main battle tanks of both countries.