WASHINGTON >> Not long ago, President Bashar Assad of Syria seemed a remote and embattled figure, with the United States threatening airstrikes and other Arab leaders denouncing him for having used chemical weapons against his own people.

Yet in recent days, he appears, paradoxically, to have turned the crisis to his advantage, making clear to a global television audience that he aims to use President Barack Obama’s own "red line" against him.

In exchange for relinquishing his chemical arsenal, Assad said Thursday, he will require that the United States stop arming the Syrian opposition – a demand that might seem wishful from the leader of an embattled county where civil war has left 100,000 dead, 2 million living as refugees and large swaths of territory beyond his control.

Assad outlined his demands Thursday, telling a Russian TV interviewer that the arms-control proposal floated by his patron in Moscow would not be finalized until "we see the United States really wants stability in our region and stops threatening, striving to attack and also ceases arms deliveries to terrorists."

Secretary of State John Kerry delivered a blunt response to Assad’s comments after meeting Thursday with Russia’s foreign minister, Sergey V. Lavrov, saying the standard procedures for identifying and securing the weapons were too slow in Syria’s case. "There is nothing standard about this process," Kerry said. "The words of the Syrian regime, in our judgment, are simply not enough."

Assad, sounding relaxed and confident, hinted in his interview that the Russian proposal – which requires Syria to sign the Chemical Weapons Convention – could become a lever for endless negotiations and delays, much as Saddam Hussein delayed arms control inspectors during the 1990s. "It doesn’t mean that Syria will sign the documents, fulfill the obligations, and that’s it," Assad said.

The state-owned Syrian newspaper Al-Watan put it bluntly in a headline on Thursday: "Moscow and Damascus pull the rug out from under the feet of Obama."

Assad’s comments on Thursday were the latest chapter in a rhetorical offensive by the Syrian president and his surrogates, who seem to feel that global perceptions of the Syrian opposition – with its strong component of Islamic radicalism – have shifted in their direction. Assad has granted interviews to American and French reporters in recent weeks, and has brought back the media adviser who had largely disappeared from public view for the past two years, a Western-educated interpreter and author named Bouthaina Shaaban.

Shaaban is a skilled interlocutor who helped Assad shape his image in the West as a reform-minded leader during the years prior to the uprising in 2011. Her re-emergence has "signaled a coherent determination to launch a media blitz," said Jon Snow, a veteran anchor for Britain’s Channel 4 news.

In recent weeks, thousands of Syrians have recorded personal appeals to members of Congress and the American public urging them to oppose an airstrike, though it is not clear whether those efforts are coordinated with their government.

For the rebels, who could often use a tip or two in the area of public relations, all of this is unqualified bad news. "It is disappointing," said Najib Ghadbian, the main Syrian opposition group’s special representative to the United States. "If the regime wants to play with this, it could take months or years. This is why we need accountability."

A rebel brigade commander named Moaz al Yousef, reached by telephone, spoke bitterly of Obama’s interest in the Russian proposal – and the delay of the congressional votes – as a betrayal.

"We had hopes, it was a dream, and now it’s gone and we feel disappointed," he said. "We should completely cut off our relationship with him – Obama has completely lost his credibility."

The rebels’ foreign backers were almost equally derisive. Recep Tayyip Erdogan, the Turkish prime minister, dismissed the Russian proposal in a speech in Istanbul on Thursday, saying that Assad was merely buying time for "new massacres."

In his interview with Russian television, Assad hinted at another possible stumbling block in the prospective chemical weapons agreement by saying Israel should ratify it first. Israel has signed the accord but not ratified it, and is extremely unlikely to do so in light of the difficulty of verifying Syrian compliance in the midst of a civil war.

For Assad, the Russian proposal comes as a welcome reprieve. Even before the chemical weapons attack on Aug. 21, his military was effectively locked in a stalemate with the opposition, despite the intervention of militia fighters from Hezbollah, the Lebanese Shiite movement, in recent months. Although Assad won a few key victories, he has still not pushed the rebels from the Damascus suburbs. That, many analysts say, was the goal of the chemical weapons attack, in a rebel-held part of the eastern suburb of Ghouta.

After the attack, Assad was clearly bracing for an American strike, with the military moving key units and the capital largely emptied out. But the congressional debate over military intervention suggested – to the Syrians – a lack of American resolve, and the Russian proposal bolstered Assad’s confidence, even at the cost of admitting for the first time the existence of Syria’s chemical weapons program.

"Assad appears to have the impression that the Americans may want him to go, but not now," said Andrew J. Tabler, a Syria analyst at the Washington Institute for Near East Policy. "So you can now expect him to go on the offensive."

Some analysts cautioned that Assad could be overplaying his hand.

"The Syrian regime swings between nihilism and triumphalism; there’s nothing in between," said one Damascus-based analyst who asked to remain anonymous for fear of retribution. "The chemical weapons deal – there is no deal, it’s very impractical, and if that becomes clear, it could put Obama in a stronger position vis-‘-vis airstrikes."

The analyst added that Assad’s comments on Thursday could be less a reflection of his own thinking than of what the Russian leadership wants him to say. "Syrian foreign policy has been contracted out to Russia, and Assad was speaking to Russian talking points," the analyst said. "That is troubling in itself."

© 2013 The New York Times Company