They were not all to serious about invading the U.S.S.R, instead they were serious about preparing a defense. Yet even then the idea of starting yet another war, a war that would be much more massive between the two super powers, just didn't seem appeasing. I have actually read somewhere that it was the English commanders and generals pushing for war more than American ones. The American generals had done their part for the most part. Western Europe was liberated, Germany was defeated, and the Americans had pushed into Germany meeting the Russian advance and stopping the spread of communist to the Atlantic. While there were some ideas from Patton, like arming the German military to fight the Russians, the majority of others didn't like the idea. Patton was a great general but was a man of war. He lived for war and even said that once wars had ended he wouldn't have a purpose. So it's easy to see why he was jumpy to fight the Russians.

Overall though neither the Allies or the Soviets wanted another war. Too much had already been destroyed and the two wanted time to rest and recover. Although they were weary of each other and plans were made to defend in case of an attack. But plans are just plans and they remained secret until the late 1990's after the U.S.S.R had fallen. So although there were plans ready just in case of a war no side actually wanted to start a war. The plans were just there so they would have options to take when the time came.