My high school history teacher was a former NBC (nuclear, biological, chemical) officer in the U.S. Army. One day he told us about some stuff he did in the army. Heres some stuff he said-
Even if the U.S. was only about to launch 1/12th of its nuclear aresenal, 95% of Russia would be destroyed.
He was also a tank commander (never said what type, I imagine M60s or M48s). He said that during the winter in Germany, they had to slave-start 75% of their tanks, and even then it was hard to get some of the tanks running at all. He said after the cold-war was over, he was able to go over to the Soviet sector of Germany. He said the Soviets had heated bunkers large enough to house a (brigade I think) of tanks. If war ever broke out, the Soviets would have been able to roll through Germany.