This interactive timeline tracks Russo-Turkish tensions
The following report is a joint presentation by the Institute for the Study of War and the Critical Threats Project at the American Enterprise Institute.
Russia and Turkey have long been at odds over Syria, with Moscow backing President Bashar al Assad and Ankara supporting the opposition to overthrow him.
Tensions increased dramatically with the start of the Russian air campaign on September 30.
The Turkish shoot-down of a Russian combat aircraft on November 24 is an escalation in this tense stand-off between Russia and a NATO member.
Although both sides may refrain from additional aggressive activities at once, tensions between Russia and Turkey have been continuously growing and are likely to expand, further testing the strength of the US commitment to its NATO partner. These tensions will also severely hinder efforts to build a "grand coalition" including Turkey and Russia.
Turkey's decision to fire on a Russian Su-24 that briefly violated its airspace resulted from more than concerns about the integrity of its borders. Russian airstrikes have been helping Assad, Hezbollah, and Iranian proxy forces advance in Turkmen areas near the Turkish border in recent days.
Turkey claims that those airstrikes hit Turkmen villages. Turkey regards the Turkmen of Iraq and Syria as kin, works to protect and advance their interests, and tries to defend them. The Turkish shoot-down is probably intended to deter Putin from continuing to provide air support to Assad operations against them, among other things.
Putin aims to disrupt NATO fundamentally as part of a larger effort to recoup Russia's losses following the collapse of the Soviet Union. He has been deliberately and aggressively prodding Turkey from his airbase in Syria, just as he has been consistently violating the airspace of US allies in the Baltics and US partners in Scandinavia. He is counting on Washington to remain so myopically focused on the fight against ISIS that it overlooks and tacitly accepts these assaults on the Western alliance structure. It would be an enormous mistake if we did so.