By the early 1960s, with the Cold War now well into its second decade, Western intelligence learned the Soviets were preparing a vastly improved version of their T-62 main battle tank with upgraded armor, three-man crew and an autoloading main gun. The U.S. and West Germany had only just fielded two new heavy tanks, the M60 and Leopard I, but already it appeared that the new Russian tank would soon have the advantage over them. In actuality, the typical “capability inflation” of Cold War-era Soviet weapon systems was in full effect. The West wasn’t to know until years later that the Soviet tanks were so cramped as to greatly reduce the efficiency of the crew, and that the autoloader for the main gun had a nasty habit of loading the extremities of unwary gunners into the cannon’s breech.

The American and West German armies faced exactly the same threat in exactly the same theater of operation. As a result, they both needed a heavy tank that could move fast, fire a very large round and withstand as much as it could dish out.

But at the time, the U.S. defense planners concluded what was needed was a tank so advanced that it would keep us ahead of the Russians for a full generation, not just a couple years. American Defense Secretary Robert McNamara decided to do something no one had ever tried before or since; he got the West Germans to agree to jointly develop this “super-tank” with the United States. The program was to be called the Main Battle Tank 70 or MBT-70.

Today, many weapon systems are developed as part of a cooperative effort by two or more allied countries. But for some reason, nobody ever tries to jointly develop tanks. Nobody really knows why, although the MBT-70 experience might provide a clue.

There was one very good reason to think that the MBT-70 project might work. The American and West German armies faced exactly the same threat in exactly the same theater of operation. As a result, they both needed a heavy tank that could move fast, fire a very large round and withstand as much as it could dish out. The other reason was that the U.S. Army was coming to the opinion that our basic tank design philosophy had already gone as far as it should. It was time for something radical.

Initially, both parties saw eye to eye on the new tank’s basic design parameters; a primary one being that it should have a much lower silhouette than the current M60, which was several feet higher than the tallest Russian tank. Instead of having the crew stations inside the hull, as was usually the case, they were being put inside the MBT-70’s oversized turret, which would be protected against nuclear, biological and chemical (NBC) threats. This also made it easier to work out the tank’s armor layout, which they agreed should consist of two spaced layers; an outer layer made of thick, hard, cold-rolled steel and an inner layer made of “soft’ steel that would also protect against “spalling,” or interior fragmentation of the armor.

As testing continued, they realized they had another big problem. Because the driver would be located inside a turret that would be rotating in battle, the tank’s designers had come up with the solution of mounting the driver inside his own contra-rotating cupola within the turret. Regardless of the direction the turret was facing, the cupola would automatically face forward. The drivers, however, accustomed to being located in a stationary position at the front of a tank’s hull, were becoming disoriented and suffering from motion sickness.

They also agreed to employ an advanced and complex hydro-pneumatic suspension system enabling it to travel cross-country at high speeds, despite its projected fifty-ton weight. The suspension would also be capable of being raised or lowered by the driver so that the tank could “crouch down” to only four inches off the ground when stationary or be raised up to a full twenty-eight inches when running cross-country.