Speaking of the role of national tensions for the USSR collapse, "underground facts" are not dull. Sam Marcy:

Another personnel change, no less significant, was the removal of Vladimir Shcherbitsky from the Politburo in September 1989. He was the only Ukrainian on the Politburo. The Ukraine is the second largest republic.

[By] 1989, of the nine full members of the Politburo when Gorbachev took over, eight had been replaced. He had obtained the firm control which it had taken others years to obtain.

[The] organizational changes were a mask for a basic shift in the political and economic spheres of the Soviet Union. But they did not by themselves constitute the kind of rupture that took place with the ouster of Dinmukhamed Kunayev, a Kazakh who was a member of the Politburo from 1966 until January 1987.

Kunayev's removal as First Secretary of the Kazakhstan Party in December 1986, and his replacement by a Russian, Gennadi Kolbin, was followed by a major rebellion in the capital of Alma-Ata. This opened wide the gates to counter-revolution and the dissolution of the USSR. It was given very little prominence in the U.S. press.

The Union of Soviet Socialist Republics was a great and unpredecented federation of socialist states based upon the equality of all nations. [The] three greatest pillars of this union were the Russian, Ukrainian and Kazakhstan republics. But after the Alma-Ata rebellion in Kazakhstan, and then the ouster of Shcherbitsky, a Ukrainian, two of the three pillars of the union had been weakened.

From the vantage point of the political struggle, these were gross violations of the rights of nationalities that could not possibly be lost on the other republics within the USSR.

And this is for a broader "perspective". Is it sour grapes from Romanov, or early perestroika (& collapse?) planning?

When Soviet President Konstantin Chernenko died, a hastily called meeting of the CPSU Politburo voted five against to elect Mikhail Gorbachev as his successor. Coincidentally (?) three opponents of Gorbachev in the Politburo, among whom was Grigori Romanov, were out of town and not present at this all-important meeting and were not notified to come immediately.

Grigori Romanov once was a powerful figure at the highest level of the Soviet State. [He] was considered one of the two possible successors to Chernenko; the other one was Vladimir Shcherbitsky. "No one seriously considered Gorbachev," says Romanov.

On the day that Chernenko died (March 10, 1985-19.20 hrs) Romanov was in Vilnius, Lithuania with his wife. They had been given a trip to the sanatorium and could only fly back to Moscow on the following day. Two other Politburo members were also at that time out of town; Dinmuhammed Kunaev was in Alma Ata, Kazakhstan and Shcherbitsky was in the United States. If these three members (the usual size of the Politburo is about 14 full members) had been present at the meeting, as they could have been the following day - Gorbachev would never had been elected, says Romanov. "By the time we arrived in Moscow, the very next day, he'd already done it without waiting for us as Politburo rules demanded. That fast! That was it... He'd already cut the deal in secret with all of them. And you think that the timing of Chernenko's death, I mean, was all accidental?.