MOSCOW – Though he likes to bet on sure things, President Vladimir Putin made an uncharacteristic gamble this week when Russia stepped into the middle of the gathering Syrian crisis. His success will depend on forces outside his control.

The Obama administration was wary when it first heard Russia’s proposal that Syria turn over its chemical weapons for destruction, coinciding with Syria’s signing on to the chemical weapons convention.

It looked as though it could have been a tactic intended to delay the impending U.S. military strike on Syria or a posturing stunt meant to embarrass Washington. But Russia had seen an opportunity Monday and leapt at the chance to show that it is still a nation to be reckoned with.

Politicians and analysts here point out that Russia has genuine reasons to step in at this moment and try to broker a deal that would forestall Western intervention as well as secure Syria’s alarmingly vast stock of chemical weapons.

“This is not a theoretical question,” Andrei Klimov, deputy chairman of the foreign affairs committee of the upper house of parliament, said Wednesday. Russia has the safety of its own citizens to protect, he said. “And we have the solution.”

The Kremlin believes that an American military strike would roil the entire Middle East and threaten to expand the conflict beyond Syria’s borders. It sees a danger in a violent reaction among Muslim extremists within Russia itself. Moscow fears that Syria’s chemical weapons could fall into the hands of radicals who wouldn’t hesitate to use them.

And there’s a question of pride: Russia poses as the counterweight to the United States. Its diplomatic initiative helps maintain that image. To be a relatively passive bystander to an American attack would be a moment of uncomfortable truth.

For the more than two years that Syrians have been at war with each other, Russia has been the consistent nay-sayer, blocking any action by the United Nations to address the conflict and providing a stalwart defense of the regime of Syrian President Bashar Assad.

Until this week, any attempt to find common ground with the West on Syria would have made Russia appear to be “dancing to the U.S. tune,” wrote Georgy Mirsky, a Middle East expert, on the website of the Ekho Moskvy radio station.

Putin wasn’t going to let that happen. Russia, in his conception, must be seen as a great power, and that precludes any agreement to toe the American line on an issue where Russia has other ideas. In 2011, Moscow went along on the intervention in Libya, which Putin quickly decided was a major error, not to be repeated.

But Monday’s chemical weapons proposal enables Russia to take center stage on its own initiative and offer a solution to part of the Syrian crisis rather than put up an obstacle.

Russia took the lead and put the question to the United States. If Washington had balked, Putin could still present himself as a thwarted peacemaker.

There are risks for Russia nonetheless. Now that the Obama administration has expressed interest, an inability to work out an agreement with the other members of the U.N. Security Council would scuttle the initiative, and Russia could get the blame. If Assad too obviously ducks his obligations to turn over chemical weapons, Russia would have to answer for him. If there is another major nerve gas attack in Syria, and it can be traced to Assad’s forces, that would be a disaster for the Kremlin.

Yet the benefit for Russia, if the plan succeeds, is clear to policymakers here. Putin’s government believes that an American military strike on Syria would have unpredictable, but almost certainly devastating, consequences. It could let loose forces of disorder, Klimov said, that might reach into Russia itself, in the Muslim areas along the Caucasus Mountains.

Russia fought two destructive wars in Chechnya, radicalizing Islamists throughout the entire southern belt of the country. Today it is fighting a low-grade war in Dagestan, where bombings, assassinations and outright assaults by guerrillas kill moderate imams and a few dozen Interior Ministry troops every month.

Russia is extremely concerned about a spillover of violence from the Middle East.

“Syria,” he said, “is closer to us than to Washington.”

In a column that was published before the Russian proposal became public, Fyodor Lukyanov, the editor of a foreign affairs magazine with a good sense of the Kremlin’s thinking, wrote about the unknowns facing President Obama — but he could have been describing Putin’s dilemmas, as well.

“The international system has reached a turning point,” Lukyanov wrote. “It is no longer possible to ignore the absence of a stable world order since the Cold War ended. Increased interdependence between countries does not guarantee the integrity of the global system. On the contrary, though inseparably linked, the world is fragmenting, and it’s hard to understand or predict what some fragments might do.”

An American strike could lead to various forms of intervention by Iran, Mirsky wrote, and Russia, which has been placing a squadron of warships in the eastern Mediterranean, would inevitably have to contend with increasing pressure to step up its own involvement.

Putin’s foreign policy values stability above all else. It views the Arab Spring as a dangerous failure that has let loose worrisome Islamist extremism, said Dmitri Trenin, of the Carnegie Moscow Center. The fall of Assad would hasten that trend, the Kremlin believes.

There’s an issue of pride, as well. If the United States takes action against Syria, Putin could savor his indignation, but he would not go to war to stop it. That would demonstrate Russia’s limited ability to move events. It would show, in other words, that Russia is not fully a country to be reckoned with.

“If you’re not equal, you can’t operate equally,” Trenin said. “Russia isn’t the Soviet Union.”

With its diplomatic proposal, Russia is able to fend off a direct comparison with U.S. prowess and remain in the thick of things.

And though Syria launched its chemical weapons program with ample help from Moscow, those arms are now in fact a major concern for the Kremlin. Russia would view with alarm a chemical weapons attack by Syria against Israel. It would consider it a catastrophe if the weapons fell into unfriendly hands — such as those of Islamic extremists.

“Even now, in this chaos, they need to remove chemical weapons for disposal under international control, without losing time,” Adm. Vladimir Komoyedov, head of the defense committee of the upper house of parliament, told the Interfax news agency Wednesday.

“God forbid, if the Assad government were to collapse, the army would disintegrate and then no one would be able to predict who would seize this chemical arsenal and how it would be used,” he said. “It would not only mean the collapse of Syria, it would harm the entire Middle East.”

Klimov laughed when asked if the Russian plan helps Obama, who was facing strong opposition at home to military action.

“You can say so, if you like,” he replied. “But we’re not thinking about how to help Mr. Obama, or Mr. Assad, or anyone else.”

Still, he added, if the proposal succeeds in persuading the Americans not to attack and the Syrians to hand over their chemical weapons, it could set the stage for further diplomacy finally to resolve the Syrian conflict itself.