Burhan Ozbilici/AP
Russian President Vladimir Putin, left, and his Turkish counterpart, Recep Tayyip Erdogan, after a joint news conference at the new Presidential Palace in Ankara, Turkey, on December 1.
Turkey, which has long sought Syrian President Bashar Assad's transition out of power, has been supporting some of the most powerful rebel groups in northern Syria since the civil war began in 2011.
A Russian bombing campaign against rebels including Turkey-backed rebel groups, however, now threatens to undermine Ankara's entire Syria policy, which has been predicated on bolstering anti-Assad rebels and establishing a "safe zone" for displaced Syrians.
It also precludes any possibility of Turkish intervention in the north.
"Turkey is shut out," Dr. Jonathan Schanzer, vice president of the Foundation for
"The question now is whether Turkey would want to openly challenge Russia," Schanzer added.
Turkey has expressed "serious concern" over the Russian airstrikes since Russia began its air campaign against the rebels on Wednesday. On Friday, Turkish Prime Minister Ahmet Davutoglu accused Russia of hitting the rebels to bolster the Assad regime.
"Turkey finds itself in a very difficult position with the Russians," Aaron Stein, a nonresident fellow at the Atlantic Council, said in an interview.
Russia's intervention on the side of Assad has further complicated Turkish President Recep Tayyip Erdogan's desire to limit the territorial gains of the Kurdish YPG along the border.
"If the Russians are able to maintain their current state of operations and they continue to strike targets along the Idlib-Latakia dividing line, that will ease the pressure off Assad," Stein said.
"As a result, Turkey's instinct will be to increase support for the rebels. But Ankara will also have to consider the possibility that bolstering the rebels further might lead weapons to fall into the hands of the YPG," the military arm of the Kurdish Democratic Union Party (PYD).
Salih Muslim, cochair of the PYD, said in an interview with al-Monitor that the Russian incursion into Syria had undermined Turkey's ability to intervene in any meaningful way - a welcomed development for the Kurds.
"Turkey's Syrian policy is totally bankrupt," Muslim said. "Two years ago I was talking to a Russian official and he asked me, 'What do the Kurds most fear?' 'Possible Turkish intervention,' I replied."
Moreover, Muslim notes, Russia's intervention will hinder the Turks' ability to impose a security zone in the north, which has long been opposed by the Kurds.
"The Russians will not meddle in the north," Muslim said. "But should Turkey attempt to intervene, then they will. Russia has a joint defense agreement with Syria. They will prevent Turkish intervention not to defend us [Kurds] but to defend Syria's border."
Rodi Said/Reuters Kurdish People's Protection Units (YPG) fighters with their weapons in Tel Hamis in Hasaka countryside on March 1.
Turkey's plans for a safe zone may be scuttled for now, but Ankara will most likely compensate by doubling down on its support for anti-Assad rebel groups such as Jabhat al-Nusra and Ahrar al Sham as the situation escalates.
"Ankara would be extremely concerned if the Russians took their campaign into Aleppo, because it opens up the possibility of another massive refugee flow into Turkey, which is already at its limits," Stein said.
There are over 1 million Syrian refugees in Turkey, about 30% of whom live in 22 government-run camps near the Syrian-Turkish border.
To prevent another refugee surge, "there will be considerations of providing the rebels with surface-to-air missiles to blunt the efficacy of Russian aircraft," he said.
In any case, the Russian intervention will lead to a hardening of battle lines on all sides.
"The Russian intervention could prompt a new phase in this conflict that could make things even bloodier," Schanzer said. "We ignore that possibility at our peril."