@Razor
Let me first start by saying that this topic deserves a much more detailed post, but for the time being let me start with a few points, about which I have thought a lot:
1. First of all , no way Gorbachev's decision though poorly implemented and at the wrong time was the main contributor to the collapse, it was a small mistake amongst many great mistakes. It was Afghanistan which was the point of no return for the Soviets, had it not been Glasnost and Prestroika of Gorbachev, it'd have been something else.
2. So why did USSR fail, to even come close to answering such a question is beyond me, but here is my take:
1. USSR peaked early, by which I mean, no one ever matched Lenin's brilliance again, Stalin if you read about him long enough finally amounts to a street thug, though a world class one, he was inhumanely tough, had little imagination, led by fear instead of inspiration' i.e- Germans planted some misinformation and he purged most of the General staff and almost lost the war, including someone like Tuckhavesky on whose concept of deep defense they later reversed the German offensive.
Each Gen. Sec. afterwards was simply less competent. Now compare it to PRC, they had their greatest leader in Den Xiao Ping, not in Mao who was just a brilliant Psychopath born in the times of chaos and took advantage. Mao concentrated power and others used that power to create something that is unimiganible, because PRC of today is anything but communist, infact they are the greatest capitalists world has ever seen, the only novelty is that, rather then letting their public live the unsustainable and ultimately counterproductive way Americans live, they use the capital gained by purest capitalistic ways to further their militiary and economic might (
at the heights of cold war USSR was spending something like 30% of its GDP on defense, while China gets away with 3% and has begun matching US, it is an indicator of howi nefficient Soviet system was), and that's why they survive and prosper where USSR failed, and that's why barring truly catastrophic luck or a debt crisis, they will make U.S. kneel, I only hope that we as a nation don't get trampled in the process.
P.S-- If the discussion progresses, then there is much more to be said