At an international forum, President Vladi­mir Putin suggested that the use of chemical weapons in an attack in Syria last month had been a clever ploy designed to discredit President Bashar al-Assad’s government and trigger a retaliatory strike. (Maxim Shipenkov/Pool/Reuters)

President Vladimir Putin made a highly unusual gesture to his political opposition Thursday: He spoke to them at a public forum. Maybe next time he’ll even give some ground.

He made no concessions to critics either at home or abroad, even though some of his aides had suggested earlier that from now on, opposition candidates could run for low-level offices without fear of arrest.

During a three-hour meeting with 200 academics and politicians from around the world, Putin suggested that the use of chemical weapons in an attack in Syria last month had been a clever ploy designed to discredit President Bashar al-Assad’s government and trigger a retaliatory strike. Russia had no special interest in Syria, he said, referring to its support for Assad over the past two years ; in opposing a U.S. plan for a strike, it was simply upholding international law, which requires U.N. Security Council authorization for the use of force.

Putin defended a new Russian law perceived as anti-gay, saying it protects minors. He spoke dismissively of political correctness and said same-sex marriages do not produce the children that Russia and European countries need to ward off demographic disaster.

He asserted that Russia does not infringe on the rights of sexual minorities. “I present these people with public awards all the time if they deserve them,” he said, adding, “We need to respect minorities, but we need to respect majorities as well.”

And, he said, he has not ruled out running for another six-year presidential term in 2018.

Putin arrived here on the fourth day of a Kremlin-supported conference dedicated to discussing Russia’s role in the world and what it should be. It was the 10th year of what’s known as the Valdai Discussion Club, which returned to its origins at a government resort in the wooded lake lands of Valdai, about 250 miles northwest of Moscow.

Putin was in the best form he has ever been in at Valdai, said Angela Stent, a Georgetown University scholar. She said he gave the impression that things are going well both domestically and in foreign policy and that he plans to stay in power for a long time.

The Valdai conferences have served as a venue for Putin to explain Russia to specialists from abroad. In other years, members of the Russian opposition have attended some events but have not been included in meetings with Putin and other high-level officials.

On Thursday, three of them were called on for questions. The day before, they had gotten some encouraging news after months of ever-harsher treatment. Kremlin officials had informed them they were now permitted to run for any local office without fear of detention. They’re allowed to be mayors — but nothing higher.

Ilya Ponomarev, a member of the national parliament who has moved into opposition in the past two years, had put the question Wednesday to Vyacheslav Volodin, Putin’s first deputy chief of staff. “If we run for office, will we be in jail after a year?” he asked. It’s fine to run for mayor, Volodin answered, according to Ponomarev and others at the meeting, but stay away from gubernatorial races.

“It’s an important shift,” Ponomarev said in an interview. “We’ll see if it’s enormous or not when it really happens.”

Ponomarev, 38, is heading straight for Siberia. He plans to run for mayor of Novosibirsk next September.

“They were cynical but sincere,” Ponomarev said of the encounter with Volodin and Sergei Ivanov, Putin’s chief of staff. “They want to create a sandbox for us.”

The Kremlin would still control all aspects of political life, Ponomarev said, but some small-scale experimentation would be authorized. “He understands the local elites make all the decisions,” Ponomarev said, “and the candidate who wants to win needs to make agreements with them.”

In July, Yevgeny Urlashov, an upstart who was elected mayor of Yaroslavl last year, was carted off to jail in the middle of the night, accused of corruption. He lingers behind bars awaiting trial on charges his supporters consider politically motivated.

One member of the opposition publicly asked Putin to ease up on harsh treatment of demonstrators. Vladimir Ryzhkov, a long-time liberal, asked Putin to grant amnesty to about two dozen demonstrators who were arrested at a protest May 6, 2012, on the eve of Putin’s inauguration.

Some of them are on trial, after being in jail for months. One was not allowed out for his grandmother’s funeral. “We can’t but agree with your words that you can’t build a strong country through violence and force,” Ryzhkov said. “That is true for Libya, Syria and Russia.”

Putin said he cannot interfere with the courts, although the courts are widely perceived here as following the orders of the powerful. “I don’t rule out amnesty, but we need to let all procedures come to their logical conclusions,” he said.

Just days ago, Putin stirred up Americans with an op-ed in the New York Times in which he criticized the notion of American exceptionalism. “The idea was mine,” he said of the piece. “I wanted to show decision-makers my thinking.”

He called an assistant and outlined what he wanted to say, he said. “After my colleagues prepared it for me, I looked through it. I didn’t like everything. I rewrote some of it.” An aide persuaded him to wait a day, until President Obama’s speech to Americans about Syria — maybe he would drop the idea of a strike on Syria. That’s when Putin added the ending, chiding the United States for seeing itself as exceptional.

“Then I gave it to my assistants, and they sent it to the New York Times,” Putin said. “There was no anti-Americanism. I only presented our position.”

He scolded Sen. John McCain (R-Ariz.) for being unfamiliar with Russia when he said he wanted to answer Putin with an article in Pravda.

“Pravda is certainly a very respected publication,” he said, “but its circulation in Russia is very low.”