BEIRUT, Lebanon — After two days of attacks directed exclusively against insurgents opposed to the Syrian government, there is little question that Russia is determined to re-establish President Bashar al-Assad as Syria’s leader.

“Russia’s goal is to defend Assad; whoever is against him is a destabilizing factor,” said Aleksei Makarkin, the deputy head of the Center for Political Technologies, in Moscow. “Russia wants Assad to get engaged in a political settlement from a position of strength.”

Yet to restore Mr. Assad to full control of Syria or, for that matter, to stitch Syria back together without putting troops on the ground, President Vladimir V. Putin of Russia will have to accomplish what no other outside power has dared attempt.

Mr. Putin can achieve a number of short-term goals. By inserting Russian military forces directly into the Syrian battlefield he can seize the initiative from Mr. Assad’s opponents and severely limit the options of the United States and its allies, not to speak of embarrassing President Obama — always a consideration for Mr. Putin.