Soviet Union collapses in late 1970-s - Post War Consensus forever?

Now, as every good Thathcer-Reagan fan knows, Soviet collapse was the result of the policies by these two politicians during 1980's. Never mind the the long-running problems from economical to ecological, or massive arms spending which did not move a bit during 1980's etc.

But what if Soviet Union collapsed already during 1970's? POD could be no Oil Crisis in 1973 which gave a short but important financial boost for USSR. So, say in 1975 Brezhnev dies and the new leadership aims for reforms but as the end result Soviet Empire collapses peacefully in late 1970's.

Does the Post-War consesus and Keynesianism continue "forever" as they've been vindicated by fall of Communism?
 
You're missing over a decade's worth of disillusionment. The Soviet Union will not collapse in the 70s, even if it goes through tumultuous reforms. In the 1970s, the regime was at its relative zenith. While real living standards were beginning to plateau, public confidence in the ruling ideology was still robust, and the first cracks were only beginning to form. Indeed, even with the massive growth of disillusionment among the intelligentsia and the public in the 1980s, we can't forget that the the Soviet Union only collapsed because the August Coup shattered support for the Soviet project, and gave nationalists the manuevering room to force the Union's dissolution.
 
Now, as every good Thathcer-Reagan fan knows, Soviet collapse was the result of the policies by these two politicians during 1980's. Never mind the the long-running problems from economical to ecological, or massive arms spending which did not move a bit during 1980's etc.

But what if Soviet Union collapsed already during 1970's? POD could be no Oil Crisis in 1973 which gave a short but important financial boost for USSR. So, say in 1975 Brezhnev dies and the new leadership aims for reforms but as the end result Soviet Empire collapses peacefully in late 1970's.

Does the Post-War consesus and Keynesianism continue "forever" as they've been vindicated by fall of Communism?
Assuming your proposition worked, who would claim power?
 
Two questions here, one about causes and one about effects.

On the first one -- A lot of things happened in the 1980s to shatter faith in the regime: Afghanistan, Chernobyl, Gorbachev's reforms, the growth of the human rights movement, eventually the coup attempt. I don't think the regime could have lasted forever by any means, but I do think it could have survived even all that if Yeltsin hadn't taken over, at least for a years longer than it did. The point is, although there are a lot of systemic problems in the Soviet Union of the 1970s, it seems to me it was probably a long way from collapse. Of course this sort of guesswork is notoriously unreliable. Seemingly failed countries like North Korea often go on looking perfectly stable and strong years after they have any right to, longer than anyone expected them to -- right up until the moment where they collapse in the space of a single weekend, and then we wonder what signs we missed. All of which to say is, "Who knows?" I guess.

On the second point -- Many people essentially DID say liberal democracy would live forever. Francis Fukuyama even called it "the end of history." Obviously they were wrong. Liberal democracy is already in at least temporary decline around the world and it hasn't even been 30 years.

That said, I think the trajectory would have to be quite different. In our timeline, the main challengers to the rule of liberal democracy are Russia, China, and Islamist fundamentalism. I think you might not have the fundamentalist contingent to deal with because historically a lot of that is closely related to the Iranian revolution and to the emergence of the mujahideen in the Soviet Afghanistan war. If you have a massive world-changing POD earlier in the 1970s, I assume Iran and Afghanistan are going to turn out quite differently.
 
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