When Vladimir V. Putin attended the annual summit of Eurasia’s main political and security organization three years ago, the Russian president seemed isolated and on the ropes.

China’s leader raised concerns about Mr. Putin’s invasion of Ukraine. India’s prime minister pointedly declared, “Today’s era is not of war.” Other heads of state left their Russian counterpart idling alone ahead of meetings. And on the battlefield in Ukraine, Moscow’s troops were collapsing in retreat.

Now, Mr. Putin’s fortunes have changed — and so has the world.

Nowhere was that more apparent in recent days than in Tianjin, China, where leaders from member states of the Shanghai Cooperation Organization, the Eurasian security grouping, met on Monday alongside heads of state from other countries.

Mr. Putin used his stage to publicly blame the West for the war in Ukraine. He gleefully held hands with Prime Minister Narendra Modi of India and erupted in laughs as the pair joined in a huddle with the Chinese leader, Xi Jinping. Leaders from Iran, Nepal, Tajikistan, Turkey and Vietnam glad-handed Mr. Putin in private meetings that ran past midnight.

“It felt like the war was accepted in certain ways,” said Maria Repnikova, a professor of global communication at Georgia State University who studies China and Russia. “It’s like back to business and the war was not even present.”

Ukraine’s Ministry of Foreign Affairs, in a statement, called it “surprising” that the summit’s final communiqué made no mention of “the largest war of aggression in Europe since World War II” despite referring to “a number of other wars, terrorist attacks and events in the world.”