Russian warplanes began carrying out strikes on rebel targets in the Homs and Hama districts of Syria Wednesday.
Russia's upper house of parliament authorized the use of military force in Syria earlier Wednesday, after President Vladimir Putin personally requested it consider the move.
"I want to say the result of the vote was a unanimous approval of the Russian president’s request," Sergei Ivanov, who heads Putin's administration, stated.
"Importantly: this is specifically about Syria. I want to underline that this is not about any kind of political objective or ambitions that we have been accused of by our western partners. It is only about international interests of Russian Federation."
Among those interests, he said, are defending Syrian President Bashar Assad's forces against rebels.
"Already a range of states are conducting rocket bomb strikes in Syria and Iraq, including the United States. France recently joined those operations," Ivanov said.
"But these actions violate international law. To be in accordance with international law, one condition must be observed: either a UNSC resolution, or a request for military assistance from the state on whose territory those strikes are to take place."
Moscow's military assistance is in response to a specific request from Assad for aid; Ivanov added that military involvement would be "temporary."
Israeli Defense Minister Moshe Ya'alon said Tuesday that "there has been unrest for four years now,” in Syria. “Despite this, we have been able to keep this threat away from the residents of the Golan Heights and the North.
"We have been following a very clear policy,” he added. “In this matter, we are intolerant toward any breach of our sovereignty. There are other developments in Syria, as well, like the Russian presence and the Iranian presence. That is in northern Syria. But we made clear to the Russians that we have no intention of abandoning our ability to defend our interests. And I suggest that no one test us.”
Putin sought to calm Israeli concerns over the deployment of Russian soldiers in Syria last week, telling visiting Israeli Prime Minister Binyamin Netanyahu his forces would act "responsibly," and noting the Syrian regime was in not a fit state to attack Israel even if it wanted to.
Netanyahu was accompanied on his trip to Moscow by his army and intelligence chiefs, in a rare step for an overseas visit. Netanyahu said he was determined to stop arms deliveries to the Hezbollah terrorist group that has been aiding Assad forces, and accused Syria's army and Iran of trying to create a "second front" against Israel.
Putin for his part said Russia's actions in the Middle East "always were and will be very responsible," and downplayed the threat by Syrian forces to Israel.