Were nuclear weapons a hoax? For the sake of this discussion, let us assume they were. Why did the Soviet Union want the nuke hoax to continue? Why did the US? Why did both?
If Poland and the other countries in Eastern Europe knew that nuclear weapons were a hoax, they might revolt and put pressure on the US to support them. As long as they believed in nuclear weapons, they could not expect the US to go to war to support their revolts. Thus the Soviet Union had a huge stake in keeping the nuke hoax going. So did the US to avoid being drawn into such a war.
Revolts in Eastern Europe came along on a regular basis even so.
East German 1953 Uprising
1968 Prague Spring
Solidarity Poland 1980
Even Ukraine could have contemplated rebellion, as well as the Baltic states and the Moslem Republics in Soviet Central Asia.
It is possible that the US and UK bought out the Soviet Union’s leadership in the 1980s. This was completed under Reagan perhaps and delayed to 1989 to put some distance. George H. W. Bush was then president when Berlin wall came down.
At that point, the Soviet leadership had Swiss bank accounts. Those were likely put together by UBS, Marc Rich and other entities, large and small. Credit Suisse also was likely part of it.
The crash of 1987 may have been engineered to push down the price of oil and help push the Soviets to sign the deal.
Year, Price of oil, Inflation adjusted price of oil
1984 $28.75 $65.36
1985 $26.92 $59.09
1986 $14.44 $31.09
1987 $17.75 $36.88
1988 $14.87 $29.73
1989 $18.33 $34.90
1990 $23.19 $41.79
1991 $20.20 $35.02
1992 $19.25 $32.39
The price of oil was pushed way down in 1986 and help down. The Berlin Wall came down in 1989, the price of oil rose in 1990 some. The Soviet Union collapsed and the republics were freed in 1991. So the price of oil was held down it appears to achieve that goal is one interpretation.
This is draft and preliminary. The above is hypotheses and speculation. Comments and corrections welcome. Please restate as questions. All other disclaimers apply.