

Although revolutionary, the project had large cost overruns, to the point that overpressure from the Bundestag caused the government to withdraw West Germany from the project in 1969. However, issues soon emerged, born from many growing divergences in specifications, measurements, and dissents over the general direction of the project.

The MBT-70 "super-tank" joint project was initiated by the USA and Germany, and studies were already well underway.

In response, Rheinmetall was already working on the L44 120 mm (4.72 in) gun, which was to be used on an upgraded version of the Leopard. At that stage, new intelligence reports stated the Soviets, who had already presented the 115 mm armed T-62, were about to start building the 125 mm (4.92 in) armed T-64. Early development started right after the Leopard came into production in 1965.
