I am afraid that was WWI, the Zimmerman telegram. As for the Soviet Union being able to take Germany on her own, I think not. Although the Soviets were able to launch a massive offensive against Army Group Center in summer 1944 after the D-Day invasion, it should be known that the western front took up a great deal of resources away from the eastern front as early as 1942. A million troops were stationed on the western front in 1944, not counting Italy, including a large portion of the Luftwaffe which was dearly needed in the east. The US's contribution was legion to the Soviet effort. The US's air forces tied down the Luftwaffe, damaged industry and kept many good units to slowly waste whilst on garrison duty. We need not mention the vast material in tanks and planes the US also gave the Soviets. Had Germany had all her resources against the Soviets from the beggining, without help from the USA, I am certain the Soviets would have not won the war. I am sure that some peace would have been reached short of total victory for either side.