From Moscow, December 25, 1991: The Last Day of the Soviet Union, by Conor O’Clery (PublicAffairs, 2011), Kindle p. 146:
By Tuesday morning, August 20, George Bush, who initially had stopped short of condemning the coup committee—on Scowcroft’s advice he had called their action extra-constitutional rather than illegitimate so as not to burn their bridges with the coup leaders—had got a better idea of what was happening. He managed to get through to Yeltsin. “Boris, my friend,” cried the U.S. president. Yeltsin was overwhelmed. “I am extremely glad to hear from you!” he shouted in response. “We expect an attack, but your call will help us.” “We’re praying for you,” said Bush.
From a balcony at the Russian White House, protected by lead shields held by Korzhakov and another bodyguard, Yeltsin read out a second statement. In it he called on soldiers and police to disobey the orders of Yazov and Pugo but not to seek confrontation.
In St. Petersburg Mayor Sobchak confronted troop commanders and persuaded them not to enter the city. At his side opposing the putsch was his special assistant, KGB officer Vladimir Putin. “Sobchak and I practically moved into the city council,” Putin recounted years later. “We drove to the Kirov Factory and to other plants to speak to the workers. But we were nervous. We even passed out pistols, though I left my service revolver in the safe. People everywhere supported us.”
Putin was concerned that his behavior as a KGB officer could be considered a crime of office if the plotters won. He expressed this fear to his boss, and Sobchak called Kryuchkov on his behalf. Astonishingly the mayor was able to get the chief organizer of the putsch on the phone to discuss such a matter of minor consequence given the scale of events—that Putin was resigning from the KGB forthwith.
Kryuchkov by now seemed to realize his mistake in not securing the arrest of Yeltsin. Public opposition was consolidating around the Russian president. The emergency committee was falling apart. Pavlov and Bessmertnykh had disappeared. Yanayev was drinking himself into a stupor. The defenders of the White House now included many high-profile personalities, including Politburo veteran Alexander Yakovlev, the cellist Mstislav Rostropovich, the poet Yevgeny Yevtushenko, and Sakharov’s widow, Yelena Bonner. Shevardnadze was also there, asking aloud if Gorbachev himself was implicated in the coup.