In 1963 the United States and Germany made an agreement to create a new main battle tank that both countries would produce, and that would be ready for production by 1970: this was the MBT-70 program.

The MBT-70 prototypes were armed with a long-barreled version of the Shillelagh gun/missile system used on the M551 Sheridan light tank and the M60A2. It was fed by a 26-round autoloader, and could fire several types of ammunition: 152mm High-Explosive/Flechette rounds; kinetic energy/white phosphorus; and the Shillelagh gun-launched ATGM. A total of 46 rounds were carried on-board.

Secondary armament comprised a remotely controlled 20mm Rheinmetall RH202 auto-cannon that was retracted and stowed in an armored housing when not in use, plus a 7.62mm coaxial machine gun.

The vehicle also had an unusual crew arrangement: the gunner was in the right front of the turret, forward of the commander; the driver was in a counter-rotating capsule in the left front of the turret; and the tank commander had controls that could also be used to drive the tank if necessary.

The tank commander had two night sights. The first was a direct sight using a light amplifier tube that fed a binocular eyepiece. The second was a low-light level TV that sent the image to TV monitors installed for the commander and the gunner.

It was powered by a 1,500hp diesel engine, and had an adjustable hydropneumatic suspension that could vary the hull's ground clearance from as little as 5.5 inches to 29 inches, and it could operate in water up to 18 feet deep.