Turkey's shootdown of a Russian Sukhoi Su-24 Fencer bomber along the Syrian border is dangerously exacerbating tensions not only in the Middle East but between Moscow and the West.

A pair of Turkish-owned Lockheed Martin F-16C fighters shot down the Fencer with AIM-120 AMRAAM air-to-air missiles.  Television footage of the incident from the state-run Anadolu News Agency shows that the two Russian pilots ejected, but it does not show if they survived crash.

While Ankara says that the Russian Sukhoi Su-24 Fencer violated its airspace, the Russians say that it did not. Moscow says it has proof that the strike aircraft was on the Syrian side of the border. “The Turkish General Staff said the downed foreign jet was issued 10 warnings in five minutes and it was shot down by two F-16s,” reads a statement from the office of the Turkish prime minister’s directorate general of press and information. “The warplane went down in Syria's northwestern Turkmen town of Bayirbucak near Turkey’s border within the framework of engagement rules.”

The Russian defense ministry confirmed that Turkish forces had downed the Su-24. “The Russian Su-24 aircraft was shot down on its way to the Hmeymim airbase in the territory of the Syrian Arab Republic by a Turkish F-16 fighter, “ the Russian defense ministry statement reads. “Analysis of the objective monitoring data definitely showed that there had not been any violation of the Turkish air space.”

Russian president Vladimir Putin responded to the incident with fury. “Today’s loss is a result of a stab in the back delivered by terrorists’ accomplices. There is no other way I can qualify what happened today,” Putin said during a meeting with Jordanian king Abdullah II in Sochi. “Our aircraft was shot down over Syrian territory by an air-to-air missile launched from a Turkish F-16 plane. It fell on Syrian territory, four kilometers from the Turkish border. When it was attacked in the air, it was flying at an altitude of 6,000 meters, one kilometer away from the Turkish territory.”

However, Ankara has released an image depicting a radar track that showed that the Russian aircraft briefly entered Turkish airspace. But Russia too has released its own evidence that its jet was over Syrian airspace when it was downed—but the photo depicts a Su-34 rather than a Fencer.

Putin stated that the downing of the Russian aircraft would not go unpunished—but it is not clear how Moscow will respond. “We will of course carefully analyze what has happened and today’s tragic event will have significant consequences for Russian-Turkish relations,” Putin said. “In any case, our plane and our pilots were in no way a threat to the Turkish Republic in any way. This is obvious.”

One immediate fallout is that Russian foreign minister Sergei Lavrov has cancelled his visit Turkey which was set for tomorrow. Russian has also summoned the Turkish defense attache in Moscow for urgent consultations according to the Russian defense ministry. Meanwhile, Turkey has requested an emergency meeting with other NATO members to bring them up to speed on the incident. U.S. officials have denied any involvement with the incident—but confirmed to the BBC that the Turkey did attempt to warn the Russian aircraft prior to shooting it down. U.S. forces are “working to establish exactly where the plane was when it was shot down,” according to U.S. Central Command spokesman Col Steve Warren per a BBC report.

Meanwhile, the BBC is reporting that one of the Russian pilots was found dead by Syrian rebels while the fate of the other remains unknown. Video evidence shows that both men came under fire from the rebel forces as they parachuted down—which is a violation of the Geneva Conventions and is a war crime. A Russian helicopter that was sent to rescue the downed pilots was also attacked.

If a conflict comes to a head, then there is plenty of room for serious military action. Both Russia and Turkey are significant military powers. The Turkish air force has more than 650 modern combat aircraft including F-16C/Ds, upgraded F-4 Phantoms and 737-based AWACS platforms. That force would be more than sufficient to wipe out the small Russian expeditionary force at Latakia because Moscow has mostly deployed strike aircraft and minimal air defenses. Turkey also has a significant navy--sixteen frigates, eight corvettes and dozen diesel-electric submarines, Ankara  could try to cut off the Russian Black Sea fleet from the Mediterranean. It could also try to invoke NATO’s Article 5 clause—but that might not apply in this situation.

Russia, of course, is a very significant power. Russia could launch tit-for-tat attacks against Turkey’s air bases or naval ports—some examples might include Turkish air bases at Konya or Diyarbakir which are near the Syrian border. Those bases could have hosted the F-16s which attacked the Russian jets. Russia wouldn’t have to worry too much about destroying Turkish air defenses—the country mostly relies on older Hawk and Rapier missile batteries and American Patriot missile systems that are deployed to the region. Russia might also be able to use the cruiser Moskva​—which is equipped with a version of the 120-mile range S-300 surface-to-air missile system—to engage Turkish aircraft if the vessel moved north toward the Syrian border.  

Make no mistake: a Russian air strike would massively escalate the situation—especially if deployed U.S. forces get involved. There are American forces deployed to bases in Turkey that could get caught in the middle. A more effective Russian response might simply be to cut off Turkey’s energy supplies. Russia supplies some sixty percent of Turkey’s natural gas supplies. Either way, the pressure is on Russian president Vladimir Putin to demonstrate that his incursion into Syria will pay off for his country--and that he is not a weakling who will supinely acquiesce to Turkey’s bold strike. The longer the Syria conflict drags on, the higher the stakes are becoming for all parties to it.

Dave Majumdar is the defense editor for The National Interest. You can follow him on Twitter: @davemajumdar.