Kayhan Ozer/Pool/Reuters Turkey's President Tayyip Erdogan (2nd R) walks with his Russian counterpart Vladimir Putin prior to their meeting at the Group of 20 (G20) leaders summit in the Mediterranean resort city of Antalya, Turkey, November 16, 2015.
These tensions finally came to a head on Tuesday, when a Russian warplane allegedly violated Turkish airspace and was shot down by Turkish F-16s.
It was an escalation of the conflict that was "not entirely unexpected," said Jonathan Schanzer, the vice president of Washington, DC-based think tank Foundation of
Nevertheless, it complicates an already muddled situation in Syria, adding layers of unpredictability to the scene.
"Syria is a very crowded military theater. Putin knew that he was making it more crowded - and complicated - when he entered Russia," Schanzer told BI by email.
Boris Zilberman, a Russia expert at the Foundation for Defense of Democracies, echoed this sentiment in an email: "It was only a matter of time this sort of incident occurred."
The incident - in which Turkey said a Russian warplane violated Turkish airspace for roughly 17 seconds - comes four days after Turkey accused Russia of bombing villages in northern Syria inhabited by Syrian Turkmen and called for an immediate end to Russia's military operation close to the border.
And in a separate affair last month, Turkey complained that at least one Russian warplane had violated Turkish airspace and that another Russian jet had locked its targeting radar on Turkish planes, The Wall Street Journal reported. It led US Secretary of State John Kerry to warn Russia about the threat of escalation.
Institute for the Study of War
In a joint press conference with French President Francois Hollande on Tuesday, US President Barack Obama said the incident "points to an ongoing problem with Russian operations" in and around Syria.
Multiple countries are striking targets around Syria right now - including the US, Turkey, France, and Russia. A US-led coalition striking ISIS-held targets near central and eastern Syria was launched in September 2014. France, Turkey, and Russia entered the fray later for different reasons.
A massive terror attack in Paris carried out by militants associated with the Islamic State earlier this month prompted France to ramp up its campaign against the group in Syria and enlist the US' help in identifying ISIS targets on the ground in Syria. Russia, meanwhile, has stepped up its airstrikes against ISIS targets in the jihadists' de-facto capital of Raqqa at France's request.
Russia had, since September, been primarily targeting rebels in Syria unaffiliated with ISIS and supported by Turkey and other countries, including the US.
'Huge egos'
Still, experts are divided on how far Russia will go to retaliate.
"I would be concerned that Russia could take a tit for tat approach and down a Turkish fighter jet at some at point in the future, but an incident in 2012 when Syria shot down a Turkish fighter jet shows that perhaps cooler heads will prevail, as that incident did not further escalate," Zilberman told Business Insider.
Geopolitical expert Ian Bremmer, the president of Eurasia Group, noted that the "huge egos" of Turkish President Recep Tayyip Erdogan and Putin "doesn't help" matters. But he argued Russia would benefit more from a measured response.
"Putin's initial reaction - calling the incident 'a stab in the back by the terrorists' accomplices' - is about as bellicose as could be imagined. But Putin is no stranger to harsh rhetoric, and he has broader interests to play for," Bremmer said.
Osman Orsal/Reuters
Russia's President Vladimir Putin (front L) and Turkey's Prime Minister Tayyip Erdogan (front R), with Foreign Ministers Sergei Lavrov of Russia (L) and Ahmet Davutoglu (C) of Turkey in the background
"There's a very significant economic relationship between the two sides - tourism, trade, and most importantly energy - that neither Putin nor Erdogan want to interfere with," Bremmer said.
Moreover, Putin has important geopolitical considerations to keep in mind.
"Putin doesn't want to create more antagonism with NATO just as he's making progress with the Europeans - France in particular - in turning back the US-led Western 'isolation' of the Russians," Bremmer added.
Philippe Wojazer/Reuters French President Francois Hollande (L) shakes hands with Russian President Vladimir Putin after a summit on the Ukraine crisis at the Elysee Palace in Paris, France, October 2, 2015.
As Schanzer said, "The fact that it was a Russian plane obviously complicates recent efforts to pull Moscow into the global anti-ISIS coalition."
Tit-for-tat
Notably, there are some subtle ways Russia could get back at the Turks - the Russian Defense Ministry has already announced that it will suspend military contact with Turkey. But it is unlikely Russia would risk a significant military escalation with NATO by doing anything more aggressive.
"Putin's immediate response has been mordant and tough, accusing Turkey of stabbing Russia in the back, of in effect protecting ISIS, and running to its NATO powers as if it has been one of its own aircraft that had been shot down," Mark Galeotti, an expert on Russian security affairs and professor of global affairs at New York University, wrote on Tuesday.
"We can expect some kind of retaliation on the political-economic front (maybe stopping Turkish airliners coming to Russian airports?) and maybe also some unloading of additional serious ordinance on Turkish-backed elements in Syria," Galeotti wrote on his blog, In Moscow's Shadows.
"However," he added, "I suspect neither Moscow nor, at the very least, the other European NATO powers will want to let this go too far."
REUTERS/Jason Reed
"Beyond a tit for tat approach, Putin could use Turkey's dependency on Russian gas to his advantage but there are economic ramifications for Russia in that sort of response as well," Zilberman said. "Additionally, Russia could go all in on arming the Kurds as well as a response."
Still, Schanzer noted, it is still too soon to say with certainty how Russia - long a fairly unpredictable actor - will respond in the coming days and weeks.
"We must now await Russia's reaction," Schanzer said. "If Russia considers this a hostile act rather than an error, we could see a crisis that invokes the charter of NATO, given Turkey's status in the multilateral organization."