More Foreign Equipment....
The Primary Nemisis.... the Soviet Army (still more!)
The T-64... high cost tank without a future?
The T-64 series was a high cost "luxury" design meant to carry the Soviet Army into the 21st Century.  However, numerous troubles developed with the vehicle, both automotively and with the fire control.  Development of the T-64 started in the early 1960s as a Soviet response to the new U.S. M-60 series tanks.  The vehicle was revolutionary in numerous ways.  It fielded an automatic loading system in a conventional turret, had a new 5 cylinder opposed-piston diesel engine, and special steel-ceramic armor that seriously degraded HEAT ammunition, and the warheads in ATGMs.  It received field trials in the late 1960s, where serious problems with the transmission and engine appeared.  These were never adequately solved, but the vehicle was fielded anyway, being deployed to tank units in Russia in the early 1970s.
There was tremendous speculation regarding the T-64s automotive, armor, and firepower capabilities.  Some sources (including Steven Zaloga) speculated the top speed of the tank at 60 mph.  Inside intel sources in the US Army indicated it was far slower than that, due to low horsepower to weight ratios.  However, the armor was of special concern, and numerous board wargames (with which this developer was involved) speculated the effects of this armor on US and NATO tactical doctrine.

There was also speculation regarding the T-64 and T-72.  In the early 1970s the thinking was they were the same vehicles, and it took some time to sort out the differences, coming to the realization that the Soviets for the first time had fielded two main battle tank designs at the same time.  While similar in appearance, the T-64 is much different from the T-72, and there are very few common components between them.

Right:  Soviet T-64s during a training exercise.
photo courtesy the Patton Museum
photo courtesy the Patton Museum
photo courtesy the Patton Museum
While these photos are not the best available, they are unique.  On the left, a T-64 bounds over a ditch and into a dirt road, the front suspension absorbing the shock.

The T-64 chassis would become the basis for the development of the T-80, while the T-72 has been used as the basis for the T-90.  The T-80 is far too costly, even for the Russians, and few are in service.