Last August was the 20th anniversary of the short-lived revanchist coup in the USSR, which led directly to the break up of the Soviet Empire.   That the coup was ultimately unsuccessful was due in large part to the bravery of Boris Yeltsin and the citizens of Moscow who protested publicly against the coup.  Their bravery was shared by sections of the Soviet military, particularly the Air Force, who also informed the plotters of their disapproval.   I understand that the main reason why the plotters did not bombard the White House, the Russian Parliament which Yeltsin and his supporters had occupied, as they had threatened was that the Air Force had promised to retaliate with an attack on the Kremlin.

A fact reported at the time in the IHT, but little-known since was that the leadership of the Soviet ballistic missile command signaled to the USA their disapproval of the coup.  They did this by moving their mobile ICBMs into their storage hangars, thereby preventing their use.  Only the USA with its satellite surveillance could see all these movements;   CIA and George Bush, aided perhaps by telephone taps, were clever enough to draw the  intended inference:  that the leadership of the Soviet Missile Command was opposed to the coup.

Here is a report that week in the Chicago Tribune (1991-08-28):

WASHINGTON — During last week`s failed coup in the Soviet Union, U.S. intelligence overheard the general commanding all strategic nuclear missiles on Soviet land give a highly unusual order.  Gen. Yuri Maksimov, commander-in-chief of the Soviets’ Strategic Rocket Forces, ordered his SS-25 mobile nuclear missile forces back to their bases from their battle-ready positions in the field, said Bruce Blair, a former Strategic Air Command nuclear triggerman who studies the Soviet command system at the Brookings Institution.

“He was defying the coup. By bringing the SS-25s out of the field and off alert, he reduced their combat readiness and severed their links to the coup leaders,”  said Blair.
That firm hand on the nuclear safety catch showed that political chaos in the Soviet Union actually may have reduced the threat posed to the world by the Soviets’ 30,000 nuclear warheads, said several longtime U.S. nuclear war analysts. The Soviet nuclear arsenal, the world’s largest, has the world’s strictest controls, far stricter than those in the U.S., they said.  Those controls remained in place, and in some cases tightened, during last week’s failed coup-even when the coup plotters briefly stole a briefcase containing codes and communications equipment for launching nuclear weapons from Soviet President Mikhail Gorbachev.”

And here is R. W. Johnson, in a book review in the London Review of Books (2011-04-28):

One of the unheralded heroes of the end of the Cold War was General Y.P. Maksimov, the commander in chief of the Soviet strategic rocket forces during the hardliners’ coup against Gorbachev in August 1991. He made a pact with the heads of the navy and air force to disobey any order by the coup plotters to launch nuclear weapons. There was extreme concern in the West that the coup leader, Gennady Yanayev, had stolen Gorbachev’s Cheget (the case containing the nuclear button) and the launch codes, and that the coup leaders might initiate a nuclear exchange. Maksimov ordered his mobile SS-25 ICBMs to be withdrawn from their forest emplacements and shut up in their sheds – knowing that American satellites would relay this information immediately to Washington. In the event, the NSA let President Bush know that the rockets were being stored away in real time.”

References:
R. W. Johnson [2011]:  Living on the Edge. London Review of Books, 33 (9):  32-33 (2011-04-28).