The Soviet Union is no more, and while there are various reasons as to its demise, certainly one of the most proximate reasons, if not the primary reason, why it all collapsed, probably comes down to the price of oil, which was and still is of extreme importance to Russia, and as it was for the Soviet Union. We find that during the 1980s, after an impressive rise in prices in the 1970s, that the Soviet Union projected that oil prices would at a minimum maintain their price of the 1970s, or probably increase, but that prediction was tragically wrong, even though oil is the engine of virtually all economies in the world, of which, without oil, countries duly suffer economically because oil is the go-to choice for transportation needs, and plays its part in electricity, heating, and for chemical concoctions of all sorts.
In the 1980s the price of oil declined for six successive years from 1981-1986, perhaps because there was a perceived overabundance of oil, and when the government of a nation has structured their budget around a much higher price, and find thus that the price has gone down, this is going to place immense pressure on that nation, of which, because the Soviet Union was overly dependent upon their main export, oil, providing it with the necessary funding to not only keep their economy humming, but to pay for necessary things such as goods and food, we find that in absence of receiving those vital things, decisions had to be made, of which, letting go of the satellite nations that made up the Soviet Union was the decision so made, for better or for worse, because at the end of the day, the top governmental officials of the Soviet Union, were Russian, and so this meant that the priority of that government on behalf of the Soviet Union was to first take care of their true motherland, namely Russia.
To doubt that oil is a major contributing factor to wars, rumors of wars, and the rise and fall of nations is to not properly comprehend that, without fuel and energy, nations are going to be forced to make difficult decisions. History tells us that Germany, Japan, and Italy, which formed the core of the Axis powers during WW II, are countries that all had a vital need to obtain oil, for without good access to such, they would not be able to wage war or conquer other nations. This thus signifies that embargoes of oil from certain nations, or the threat to do so, are going to have consequences, not only to the possible stability of the governments so affected, but the decisions subsequently made.
Indeed, in all probability, had oil continued its assent upwards in price, during the 1980s and beyond, the Soviet Union would still exist, and would also be a more formidable economic power, because oil exporters are the same that bring in an abundance of revenue for the benefit of the nation; whereas, those that must import such at an unfavorable price or without an ironclad guarantee that the oil will continually flow to them, have a much harder time of it, signifying that oil has an outsized effect upon worldwide affairs, and should be seen as often being the most significant reason as to why nations rise and nations fall.