Plausibility Check : Surviving USSR (or greater Russia), Fall (and breakup) of China

[Yuelang]

Title said that, have the USSR and China undergo opposite fate in the late 20th century. That USSR either survives to 21th century whole in geographic area, or there could be fall of communism but the resulting successor Nation is essentially unbroken USSR in term of Area covered.

All while China falls and become fragmented in minimum four quarelling successor Nations who hates each others...

POD is after the Start of Chinese Cultural Revolution.

 

[Bakenellan]

For USSR more successful economic reforms of late 1960s may do the trick. Political collapse in Russia happened due to economical collapse of late 1980s, while China underwent successful economic transformation before even attempting any political evolution.

For China remove Deng Xiaoping from power and make Tiananmen protests succeed to trigger political reforms in faulty economics.

Still USSR in 1960s already used up it's cheap manpower but failed to transform into postindustrial stage. It may be too late to save it. Some more cohesive union of Russia, Ukraine, Belorussia and Kazakhstan (with Central Asia republic maybe) is possible but I doubt it. Nobody wanted to stay.