At 7.05 p.m. Turkish time yesterday, the Russian ambassador, Andrei Karlov, was shot dead in an Ankara art gallery. The assassin, Mevlüt Mert Altıntaş, an off-duty Turkish police officer in a suit and tie, calmly shot Karlov in the back several times; spoke in Turkish about Aleppo, with his hand in the air, one finger pointed upward (a jihadi sign, symbolising ‘takbir’, the greatness and oneness of Allah); and then said, in accented Arabic, a few sentences associated with Jabhat al-Nusra. (We can be sure of all this because the shooting was captured by an Associated Press photographer.) Altıntaş was killed by security forces who stormed the building. Vladimir Putin was informed of the assassination while on his way to watch a play written by Alexander Griboyedov, Nicholas I’s ambassador to Persia, who was killed in 1829 when a mob stormed the Russian embassy in Tehran.

Karlov did not have his own security detail in Ankara. Turkey, which has been under a ‘state of emergency’ since the failed coup attempt in July, seems to have been surprisingly lax about security at the Russian-sponsored exhibition. The Turkish government has made strenuous efforts to lay the blame for the humanitarian crisis in East Aleppo on Assad and Iran alone, but there were mass protests in front of the Russian embassy all last week. Erdoğan and Putin may very well have been reconciled in July, and by all indications have struck a power-sharing deal in Syria, but Erdoğan’s base, galvanised for many years by his vehement anti-Assad rhetoric, do not seem ready to follow him in this U-turn.

Both Russian and Turkish officials declared immediately after the assassination that the real target was Russian-Turkish friendship. Despite his self-proclaimed association with al-Nusra, the Syrian conflict and his ‘takbir’ sign, many Turkish pro-government sources have already labelled Altıntaş a ‘Gülenist’: yet another member of the shadow movement that President Erdoğan blames for all Turkey’s problems, from the 15 July coup attempt to the downing of a Russian jet on the Syrian border in 2015. The people propagating this theory point to the well-documented infiltration of the police force by Gülenists, the fact that the assassin’s brother-in-law used to work at a ‘Gülenist’ school, reports that the assassin was on leave from duty from 16 to 18 July, and the fact that the assassin made the takbir sign with his left hand, which supposedly disqualifies him as a genuine believer.

But Fethullah Gülen has denied any involvement in the assassination, Altıntaş did not himself attend any school associated with Gülenists and, unlike tens of thousands of his co-workers, had survived multiple purges of the police force targeting suspected Gülenists. According to some reports, he even served on Erdoğan’s security detail last year. The left-hand argument is especially odd, given that Gülenism, too, is an Islamic movement.

It seems likely, however, that the Turkish state will continue to blame the assassination on Gülenists, while avoiding difficult questions about its all-but-open support for al-Nusra in Syria. For the moment, Russia does not have a strong incentive to contradict this version of events, which has the added bonus of putting the US on the hook. Gülen lives in exile in Pennsylvania and many Turks believe he is backed by the CIA. Vladimir Zhirinovosky, the far-right Russian senator and an ally of Putin, accused ‘Nato secret forces’ of organising the assassination before the night was out. In any case, the growing strain in Turkish-US relations suits Putin.

That said, it makes more sense for the Russian state, given its goals in Syria, to take the assassin at his word and label the killing an act of terror carried out by radical Islamists. There have been serious allegations that al-Nusra has enjoyed logistical support from Qatar and Turkey; Erdoğan argued in both February and June 2016 that the West was being hypocritical in its treatment of al-Nusra compared to the Kurdish PYD, since both were fighting Islamic State but only the latter was supported by the West. More recently, Erdoğan is supposed to have used his influence with the group in arranging the evacuation of Eastern Aleppo. If, as seems likely, Putin moves to punish al-Nusra in Syria for Karlov’s assassination, Erdoğan will not be able to stand in his way. This will also put significant pressure on his erstwhile alliance with the Saudis and Qatar. In the meantime, by all indications, Putin will have Trump in his corner when he goes after al-Nusra and other Islamist rebels. Trump has declared that radical Islamists were to blame for Karlov’s assassination.

In sum, the murder will strengthen Russia’s position in Syria against anti-regime forces. The so-called Turkish-Russian partnership won’t be hurt, but it won’t be much of a partnership either. Turkey has lost what little leverage it had with Russia, and an increasingly isolated Erdoğan will have no choice but to do Putin’s bidding. It gets worse: Turkey is already a highly polarised country, and one strategy Erdoğan has used to secure loyalty to his person has been to fan Islamist sentiment and neo-Ottoman fantasies in the special units of the police force. These sentiments have now cross-fertilised with the particular hatreds of the Syrian Civil War, and Erdoğan seems to be no longer in control of them.