Putin sees the Ukraine war as part of his battle to undo Gorbachev’s legacy.

The day that Russia invaded Ukraine, Feb. 24, the legacy of Mikhail S. Gorbachev loomed over President Vladimir V. Putin’s predawn speech.

“The paralysis of power and will is the first step toward complete degradation and oblivion,” Mr. Putin intoned, referring to the Soviet Union’s collapse. “We lost confidence for only one moment, but it was enough to disrupt the balance of forces in the world.”

For Mr. Putin, the end of the Soviet Union was the “greatest geopolitical catastrophe of the century,” a “genuine tragedy” for millions of Russians because it left them scattered across newly formed national borders. The disaster was caused, in Mr. Putin’s telling, by the weak nerves of a leader too willing to bend to the demands of a treacherous and duplicitous West — a mistake, the Kremlin’s televised propaganda now often reminds viewers, that Mr. Putin is determined not to repeat.

In Ukraine, Mr. Putin is fighting in the shadows of the empire whose end Mr. Gorbachev presided over, having started a war that has killed thousands in the name of restoring Moscow’s dominance over what the Kremlin claims to be Russian lands. But Mr. Putin’s battle to reverse Mr. Gorbachev’s legacy extends beyond territorial control to the personal and political freedoms that the last Soviet president ushered in — and that the Kremlin is now fast reversing.

“All of Gorbachev’s reforms are now zero, in ashes, in smoke,” a friend of his, the radio journalist Aleksei A. Venediktov, said in a July interview. “This was his life’s work.”

Mr. Gorbachev was still in power when Mr. Venediktov’s freewheeling liberal radio station, Echo of Moscow, first went on the air in 1990 and came to symbolize Russia’s newfound freedoms. After Mr. Putin ordered troops into Ukraine in February, the Kremlin forced the radio station to shut down.

And Novaya Gazeta — the independent newspaper that Mr. Gorbachev used his Nobel Peace Prize money to help found in the early 1990s — was forced to suspend publication in March, threatened by a new wartime censorship law.

Mr. Gorbachev, in ill health, said nothing himself publicly this year about the war in Ukraine. His Gorbachev Foundation, a research institute that “seeks to promote democratic values,” issued a statement two days after the invasion began calling for a “speedy cessation of hostilities” and “the immediate start of peace talks.”

But Mr. Gorbachev, the son of a Ukrainian mother and a Russian father, backed Mr. Putin’s view of Ukraine as a “brotherly nation” that should rightfully be in Russia’s orbit. He supported Mr. Putin’s annexation of the Ukrainian peninsula in 2014, describing the move as representing the will of the region’s population. And he castigated the West for “trying to draw Ukraine into NATO,” warning that such attempts “will not bring anything but discord between Ukraine and Russia.”

But he appeared confident that the worst could be avoided. Asked about tensions between Ukraine and Russia in 2014, he told a Siberian news outlet, “A war between Russia and Ukraine — this is absurd.”