Although committed to preserving the Soviet state and its Marxist–Leninist ideals, Gorbachev believed significant reform necessary for survival. He withdrew troops from the Soviet–Afghan War and embarked on summits with United States president Ronald Reagan to limit nuclear weapons and end the Cold War. Domestically, his policy of glasnost ("openness") allowed for enhanced freedom of speech and press, while his perestroika ("restructuring") sought to decentralize economic decision-making to improve its efficiency. His democratization measures and formation of the elected Congress of People's Deputies undermined the one-party state. Gorbachev declined to intervene militarily when various Eastern Bloc countries abandoned Marxist–Leninist governance in 1989–1992. Internally, growing nationalist sentiment threatened to break up the Soviet Union, leading Marxist–Leninist hardliners to launch the unsuccessful August Coup against Gorbachev in 1991. In the coup's wake, the Soviet Union dissolved against Gorbachev's wishes. After resigning from the presidency, he launched the Gorbachev Foundation, became a vocal critic of Russian presidents Boris Yeltsin and Vladimir Putin, and campaigned for Russia's social-democratic movement.
Given this reference text about Gorbachev, tell me whether he was an ally of Yeltsin and Putin.
According to this passage, Gorbachev was neither an ally of Yeltsin nor of Putin. In fact, he was a vocal critic of both of them.