Reviewing the history of international relations in the modern era, which might be considered to extend from the middle of the seventeenth century to the present, I find it hard to think of any event more strange and startling, and at first glance more inexplicable, than the sudden and total disintegration and disappearance from the international scene, primarily in the years 1987 through 1991, of the great power known successively as the Russian Empire and then the Soviet Union. –George Kennan, 1995

The collapse of the USSR blindsided many of the foreign policy experts, diplomats, and Kremlinologists in 1991. For example, Paul Kennedy’s 1988 bestseller The Rise and Fall of the Great Powers asserted that while Soviet decline was palpable and visible, a collapse was highly unlikely. Kennedy toyed with notions of a Soviet retreat into its own ethnic base in the end of his section on Soviet power, but discounted such a possibility as ahistorical given that all historical precedents of a retreat only came after defeat in a great power war. Kennedy’s myopia is instructive given that many commentators in this period tended to treat both glasnost and perestroika as evidence of reform and as ushering in a new period of Soviet history not unlike the post-Stalin Thaw. What blinded many public intellectuals was what they only later came to see later: Gorbachev’s reformism were a symptoms of the failures of the late Soviet system.

The crux of the matter is that the conventional wisdom of 1989-1991 did not seriously entertain the thought that the Soviet elite would voluntarily disestablish its own power base, the Soviet state. Although the Communist Party was no longer had as many barriers to its membership as in earlier Soviet periods, belonging to the Party still was the major glue within the state and administrative apparatuses of the USSR. To democratize the Soviet political system would be to end this monopoly on power. Again, historical precedents made this option seem very unlikely. The 1989 Tiananmen Square crackdown led many commentators to believe that the Communist systems were predicated upon force if put to the wall. In a 22 December 1990 New York Times editorial, Richard Pipes incorrectly maintained that Gorbachev had sided with Communist hardliners within the military and KGB:

The right-wingers -- that is, the generals, the K.G.B. establishment and the nomenklatura of the party -- are moving into a position of authority and forcing Gorbachev to choose, and he has chosen to go with them. If they win, we will see great restrictions on freedom in the Soviet Union and deterioration in foreign relations, combined with increased military activity. The Soviets will put impediments in the way of concluding and implementing various arms-reduction agreements. The Soviet military budget is likely to increase rather than diminish. Perestroika has been finished for some time. Perestroika has achieved its goal, which is to dismantle a totalitarian regime, but it failed in putting anything in its place.

The collapse of the Warsaw Pact states bolstered this pessimism about the Soviet leadership’s commitment to continued reform and democratization. Again, the conventional wisdom held that the Kremlin had seen what happened when there was too lax of an attitude towards open displays of dissidents. The Baltic states’ votes for independence created less confidence that the Soviet government could manage democratic reforms. The Wall Street Journal ran an editorial “Tiananmen in Vilnius” in 27 March 1990 which asserted wither Gorbachev will crackdown or face the destruction of the Soviet state. The use of Soviet special forces in Lithuania in January 1991, which resulted in 13 deaths, seemed to confirm this suspicion. Even the conciliatory attitudes towards Gorbachev were predicated on the common logic that there was a limit to Soviet democratization its leadership would not pass. The New York Times’s 8 April 1990 editorial “Lithuania Is Not Tiananmen Square” emphasized that:

Mr. Gorbachev may or may not be willing to go along with Lithuanian independence at some point. It is obvious that whatever his inner feelings, he has no choice but to oppose Lithuania's unilateral declaration of independence. No Soviet leader's power could survive the destruction of the Soviet empire at this time. But he is a far better bet to allow independence, in time, than any of the Russian nationalists, generals and secret police who probably would succeed him.

Running throughout many of these editorials is the notion that in some form, the Soviet state would continue, either as a federation or under a Deng-like repression mixed with free-market reforms. The third option, dissolution, was invoked only as the least likely alternative that would happen only if the Soviet leadership did not act.

After the collapse of the USSR, it became a common trope among some Kremlinologists and Soviet specialists to play the “historians should never predict the future” card. However, there also was a subset of public intellectuals that would retroactively claim an acute foresight, especially those on who fell under the rubric of conservative opposition to the Soviet system, such as Pipes. While there is some truth to this claim, their predictions of the bankruptcy of the Soviet system are there in their writings, it misses the forest for the trees. Rereading the conservative analyses of the Soviet Union, two major elements stick out. One, the Soviet state is militarily far more powerful than it was in reality. Secondly, the conservative critiques presuppose that the USSR’s leadership was far more ideologically united and were bound together by a belief in Communist dictatorship. Both suppositions are pretty far off the mark of Soviet reality; although its military was vast, it was not a pliant instrument and was riven with its own institutional conflicts, and the Soviet leadership was far less cohesive in this period. To acknowledge these prescient insights into Soviet collapse, one has to ignore the statements of shrill pessimism that surround them.

The long and the short of it is most public intellectuals did not really appreciate the Soviet Union was collapsing and only recognized so after its dissolution was a fact.

I'm sorry I don't have the answer to your particular and interesting question, but perhaps you might be interested in this slightly relevant tidbit.

It was George Kennan, a diplomat stationed at the U.S. Embassy in Moscow at the time, who in 1947 put together an analysis of US-Soviet relationship in terms of foreign policy, the Sources of Soviet Conduct. He predicted potential high instability on the side of the Soviets, and that there would be no friendship, only rivalry, between the two nations as their ideological and economic systems were simply incompatible. He also predicted that if the U.S kept constant pressure on the USSR, it might force it to adapt and change, perhaps eventually turn into something more approachable.

Consequently, a large extent of U.S. foreign policy towards the USSR was predicated on the assumption that it should be contained, denied the opportunity to spread, and constantly faced with frustration, and it will eventually lead to its collapse. Again, this was as early as 1947.

"It would be an exaggeration to say that American behavior unassisted and alone could exercise a power of life and death over the Communist movement and bring about the early fall of Soviet power in Russia. But the United States has it in its power to increase enormously the strains under which Soviet policy must operate, to force upon the Kremlin a far greater degree of moderation and circumspection than it has had to observe in recent years, and in this way to promote tendencies which must eventually find their outlet in either the breakup or the gradual mellowing of Soviet power. For no mystical, Messianic movement -- and particularly not that of the Kremlin -- can face frustration indefinitely without eventually adjusting itself in one way or another to the logic of that state of affairs."

-- George Kennan, Sources of Soviet Conduct, 1947