There are a couple of points here that are glossed over that need to be readdressed... First, the USSR didn't collapse because it was a 1-man island... Look at any map of Europe between 1945 and 1989 and you'll see that the USSR was pretty cozy in fellow Communist regimes; the problem was that the the Soviet Union's economy was driven by a government too unimaginative and too late in its response to the growing demand for the high-tech industry. The USSR industrialized faster than any nation ever had or has when Stalin came to power, but that strength became detrimental to the economy's post-WWII success, especially once the global economy slowed, because it was too rigid and focused on industry to see the wave of the future. By the time of Brzehnev and Gorbachev's reforms it was already too late. Aside from that entirely, the Soviet Union, as it was established and run, is a pretty paltry example of a Marxist state anyway. Comparing the USSR to Marx's ideals is like comparing the US to Plato's; neither looks too good compared to the accepted ideal of the ideology they adhere to.
And, also, we owe a lot to the Soviet Union; first for pretty much single-handidly defeating the Nazis in World War II for a good number of years (this is debatable), but second, for posing as an imminent threat to US national security for so long, keeping us focused on one enemy politically, militarily, and economically. The Economic Miracle owes it success to the fact that the USSR and US were caught in an ideological blinking contest, and each wanted to rebuild its half of Europe as fast as possible to curb the spread of Communism in the West and liberal democracy in the East as well as to have strong military allies. Without the Soviet Union, it's not hard to imagine most of Europe still rebuilding from the carnage that was that war.
Happy Birthday, Karl.