Adopting principles of glasnost and perestroika, he weighed the legacy of seven decades of Communist rule and set a new course, presiding over the end of the Cold War and the dissolution of the U.S.S.R.
Mikhail S. Gorbachev, whose rise to power in the Soviet Union set in motion a series of revolutionary changes that transformed the map of Europe and ended the Cold War that had threatened the world with nuclear annihilation, has died in Moscow. He was 91.
His death was announced on Tuesday by Russia’s state news agencies, citing the city’s central clinical hospital. The reports said he had died after an unspecified “long and grave illness.”
Few leaders in the 20th century, indeed in any century, have had such a profound effect on their time. In little more than six tumultuous years, Mr. Gorbachev lifted the Iron Curtain, decisively altering the political climate of the world.
At home he promised and delivered greater openness as he set out to restructure his country’s society and faltering economy. It was not his intention to liquidate the Soviet empire, but within five years of coming to power he had presided over the dissolution of the Union of Soviet Socialist Republics. He ended the Soviet debacle in Afghanistan and, in an extraordinary five months in 1989, stood by as the Communist system imploded from the Baltics to the Balkans in countries already weakened by widespread corruption and moribund economies.
For this he was hounded from office by hard-line Communist plotters and disappointed liberals alike, the first group fearing that he would destroy the old system and the other worried that he would not.
It was abroad that he was hailed as heroic. To George F. Kennan, the distinguished American diplomat and Sovietologist, Mr. Gorbachev was “a miracle,” a man who saw the world as it was, unblinkered by Soviet ideology.
But to many inside Russia, the upheaval Mr. Gorbachev had wrought was a disaster. President Vladimir V. Putin called the collapse of the Soviet Union the “greatest geopolitical catastrophe of the century.” For Mr. Putin — and his fellow K.G.B. veterans who now form the inner circle of power in Russia — the end of the U.S.S.R. was a moment of shame and defeat that the invasion of Ukraine this year was meant to help undo.
“The paralysis of power and will is the first step toward complete degradation and oblivion,” Mr. Putin said on Feb. 24, when he announced the start of the invasion, referring to the collapse of the Soviet Union.
Mr. Gorbachev made no public statement of his own about the war in Ukraine, though his foundation on Feb. 26 called for a “speedy cessation of hostilities.” A friend of his, the radio journalist Aleksei A. Venediktov, said in a July interview that Mr. Gorbachev was “upset” about the war, viewing it as having undermined “his life’s work.”
When he came to power, Mr. Gorbachev was a loyal son of the Communist Party, but one who had come to see things with new eyes. “We cannot live this way any longer,” he told Eduard A. Shevardnadze, who would become his trusted foreign minister, in 1984. Within five years he had overturned much that the party held inviolable.
Mr. Gorbachev’s first five years in power were marked by significant, even extraordinary, accomplishments:
■ He presided over an arms agreement with the United States that eliminated for the first time an entire class of nuclear weapons, and began the withdrawal of most Soviet tactical nuclear weapons from Eastern Europe.
■ He withdrew Soviet forces from Afghanistan, a tacit admission that the invasion in 1979 and the nine-year occupation had been a failure.
■ While he equivocated at first, he eventually exposed the nuclear power-plant disaster at Chernobyl to public scrutiny, a display of candor unheard-of in the Soviet Union.
■ He sanctioned multiparty elections in Soviet cities, a democratic reform that in many places drove stunned Communist leaders out of office.
■ He oversaw an attack on corruption in the upper reaches of the Communist Party, a purge that removed hundreds of bureaucrats from their posts.
■ He permitted the release of the confined dissident Andrei D. Sakharov, the physicist who had been instrumental in developing the Soviet hydrogen bomb.
■ He lifted restrictions on the media, allowing previously censored books to be published and previously banned movies to be shown.
■ In a stark departure from the Soviet history of official atheism, he established formal diplomatic contacts with the Vatican and helped promulgate a freedom-of-conscience law guaranteeing the right of the people to “satisfy their spiritual needs.”
But if Mr. Gorbachev was lionized abroad as having helped change the world — he was awarded the Nobel Peace Prize in 1990 — he was vilified at home as having failed to live up to the promise of economic change. It became widely said that in a free vote, Mr. Gorbachev could be elected president anywhere but the Soviet Union.
After five years of Mr. Gorbachev, store shelves remained empty while the union disintegrated. Mr. Shevardnadze, who had been his right hand in bringing a peaceful end to Soviet control in Eastern Europe, resigned in late 1990, warning that dictatorship was coming and that reactionaries in the Communist Party were about to cripple reform.
Peter Reddaway, an author and scholar of Russian history, said at the time: “We see the best side of Gorbachev. The Soviets see the other side, and hold him to blame.”