Ammon News - AMMONNEWS - In an incident that will likely have serious repercussions for the air war against the Islamic State in Syria and relations between NATO and Russia, Turkish aircraft shot down a Russian fighter plane on Tuesday after Ankara said it crossed into Turkish airspace.

The downing, and what appears to be the death of at least one Russian pilot, realizes one of the worst fears of policy makers and military leaders about the close proximity of NATO and Russian warplanes operating in Syria, and stands as the most serious incident between Russia and a NATO nation in recent memory. The downing of the Russian jet also highlights the difficulties that the anti-Islamic State coalition would face in enforcing a no-fly zone in northern Syria, a proposal rejected by the Obama administration, but which has been touted by many Republican presidential candidates, as well as by Democratic front-runner Hillary Clinton.

Russian President Vladimir Putin has already reacted strongly to the downing of the plane, calling the Turkish action a “stab in the back by the terrorists’ accomplices.” In comments during a meeting with Jordanian King Abdullah, Putin warned that the incident would have “significant consequences” for Moscow’s relations with Turkey.

NATO has called an “extraordinary meeting” in Brussels after the shooting down of the Russian jet. It’s not clear what measures, if any, the alliance will announce but the incident poses a thorny dilemma for the Obama administration and its allies in the anti-Islamic State fight, who have already been concerned that Putin was using his air war there to prop up the teetering regime of Syrian strongman Bashar al-Assad rather than his stated goal of bombing ISIS targets.

In the wake of the Paris terrorist attacks, several NATO members are publicly discussing increasing their contribution to the air war in Syria, which would only increase the traffic in an already crowded airspace.

Last month, the United States and Russia signed a memorandum establishing a communications network between pilots from the two countries to avoid midair confrontations over Syria, and there have been no reports of near misses between American and Russian jets.

The downing occurred near the Syrian border, though Russian and Turkish officials sharply dispute which side of the border. The Turkish military has said that it warned the jet to turn around “10 times within five minutes” when it strayed into Turkish airspace, though the Russian Ministry of Defense insists that “the aircraft was flying only within the borders of the Syrian territory.” Video footage shows the Russian Su-24 jet falling to the ground in flames, with two parachutes visible. A Syrian insurgent group in Syria has claimed its fighters fired at the pilots as they descended, and has released video showing what appears to be the corpse of a bloodied pilot who appears to be one of the Russians.

The incident comes at a moment of increasing tensions between Turkey and Russia, as Ankara has been unhappy with Russian shelling of Turkmen villages in northern Syria, and summoned Russian ambassador, Andrey G. Karlov, to complain just last week.

In response to Russian drones and jets skirting the Turkish border since its air war in Syria began in September, Washington deployed six U.S. Air Force F-15 fighters with air-to-air combat capabilities to Incirlik Air Base in Turkey earlier this month. The U.S. European Command said the move came “in response to the government of Turkey’s request for support in securing the sovereignty of Turkish airspace.”