The killing of Russia's ambassador makes a bad situation much worse

Ambassador Andrey Karlov didn't stand a chance. He didn't even see the gunman coming.

Behind him, over his right shoulder, a man in a in suit and tie was pulling his pistol before pointing it in the air and shouting: "Allahu akbar (God is greatest). Do not forget Aleppo! Do not forget Syria! Do not forget Aleppo! Do not forget Syria!"

The first bullet hit and Russia's ambassador to Turkey fell to the floor. It was all over so fast, but the repercussions will resonate across the region a long time to come.

The context of both the domestic political situation in Turkey and its current relationship with Russia -- largely framed by their surprising cooperation in Syria -- is crucial to understanding the potential magnitude of Monday's attack.

Not only is Turkey facing almost weekly attacks from Kurdish separatists and less frequent but just as deadly attacks by ISIS, it is struggling to recover from a coup attempt earlier this year that's hobbling its economy.

The image of a nation limping from one crisis to the next looms large, but even on the scale of Turkey's everyday struggles, this peaks the meter.

In recent weeks, Russia had seemed increasingly important to Turkey. President Recep Tayyip Erdogan has been talking with Moscow more and more frequently, helping arrange the safe passage of Aleppo's civilians out of the devastated Syrian city. He was planning to visit the Russian capital December 27 to discuss a grand strategic peace deal in Syria with President Vladimir Putin and his Iranian allies.

It's a 180-degree turnaround from where relations between the two nations stood this time last year. Turkish jets had shot down a Russian fighter aircraft on the Syrian border, because, Turkey says, it strayed into its airspace.

Erdogan's NATO allies were shocked: the last thing they needed was to trigger a full-blown confrontation with Russia when tensions between the West and Russia were already sinking to Cold War lows.

The thaw between Russia and Turkey this summer was realpolitik writ large. Though that shouldn't have come as a surprise: Russia is dominating in Syria and today can dictate both what a peace deal will look like and who can play a role in brokering that deal.

For a while, Turkey backed Syrian rebels who were fighting the forces of Syrian President Bashar al-Assad. It even looked to the US as an ally to help remove the Syrian President from power.

But Russia's intervention and the lack of US leverage and negotiating power left Turkey sidelined, putting Putin in the pole position.

Erdogan has fought long and hard to make sure Turkey has a role in Syria's future and has clearly concluded that Putin is the man who can help make that happen.

So the death of the Ambassador on Turkish soil will not only be an incredibly awkward embarrassment for Erdogan, but may dent their shiny new friendship.

At first glance the attack seems to have a religious motivation. The gunman shouted "Allahu Akbar", but there is no guarantee he represents Muslims of any sort.

No doubt many Syrians -- moderate and extreme -- harbor ill will towards the Russian government for what the UN has called "indiscriminate" bombing in Aleppo and the carnage across the whole of Syria. But Erdogan won't rule out anyone without evidence.