Russian Ambassador Andrei Karlov was assassinated in Ankara on Monday by a man assigned by Turkey to protect him. And much of the world could watch the very moment almost instantly, and listen to the killer's boasts of vengeance for Russia's bombing of Aleppo, Syria. In a year of sudden and unexpected stresses to the global order, this one was perhaps the most immediately frightening — but it might not actually change much.

The assassination occurred the day before a meeting between Russian, Turkish, and Syrian ministers was set to take place. The government of Syrian President Bashar al-Assad had just recaptured Aleppo, and the three countries were eager to discuss the near-term future of the conflict. But suddenly the two outside powers that put themselves in a position to underpin a political settlement in Syria seemed in danger of falling out. After reaching something like a recent nadir one year ago, when Turkish jets shot down a Russian plane near Syria, relations have been improving as Turkey and Russia work together on their shared interests in northern Syria.

Turkish President Recep Tayyip Erdogan has been particularly anxious to achieve at least some kind of understanding with Vladimir Putin's regime in Moscow, both because Russia now seems determined to play a larger role in the Middle East and because Erdogan's own government recently contended with a coup that he blamed on people loyal to the exiled, U.S.-based Turkish preacher Muhammet Fethullah Gülen. At a time when Erdogan's government seems to be challenged from within, settling a quarrel with a major regional power became a priority.

But Karlov's killing highlights the way in which some dissenting elements within Turkey are far more advanced in their Islamist passions than Erdogan himself, and willing to act on them even as they are on duty for the government. Even though the video clearly shows the assassin exulting in his crime as vengeance for Aleppo, shouting a signature al-Nusra phrase, Turkish government sources and Turkish media are saying the killer is a Gulenist. That would be convenient for Erdogan, since he continues to imprison thousands of people in his effort to rout the forces that staged a coup against him. If the assassin is a Gulenist, the fresh outrage can be translated into continued support of this campaign. In truth, Erdogan may also face another internal challenge, from Dogu Perincek, the ultra-nationalist who has loyalists in the military itself.

Still, Russian and Turkish interests might find a way of staying aligned.

In the heat of passion, some Russian defense policy experts let out their anger about American support of moderate and not-so-moderate Syrian rebels. Russia's editor of National Defense, Igor Korotchenko, complained that this was not a single-man operation, but a “conspiracy” that stretched across the oceans.

The initial reaction from the Russian and Turkish governments has also been to downplay the idea of any mutual hostilities. Both want to proceed with their meetings on Syria in the coming days. Both vow to investigate the killing further, and both seem likely to use it as an occasion to redouble their efforts to suppress the enemies they have deemed terrorists, whether in Turkey or Syria.

But Erdogan's desire to appease Putin, and Putin's determination to get a good deal in the bargain, may mean a few adjustments to their relationship. The question left over is whether the Turkish people can be made to accept these terms when they come.