Turkey is a mere vassal state, the eastern arm of NATO, which is the European arm of the Pentagon. The Pentagon already issued a denial -- which, considering their spectacular record of strategic failures cannot be taken at face value. Plausibly, this might have been a power play by the neocon generals who run the Pentagon, allied with the neocon-infested Obama administration.
The privileged scenario though is of a vassal Turkey led by Sultan Erdogan risking a suicide mission out of its own, current, desperation.
Here's Erdogan's warped reasoning in a nutshell. The Paris tragedy was a huge setback. France started discussing close military collaboration not within NATO, but with Russia. Washington's unstated aim was always to get NATO inside Syria. By having Turkey/NATO -- clumsily, inside Syrian territory -- attacking Russia, and provoking a harsh Russian response, Erdogan thought he could seduce NATO into Syria, under the pretext (Article 5) of defending Turkey.
As Bay-of-Pigs dangerous as this may be, it has nothing to do with WWIII -- as apocalyptic purveyors are braying. It revolves around whether a state which supports/finances/weaponizes the Salafi-jihadi nebulae is allowed to destroy the Russian jets that are turning its profitable assets into ashes.
Married to the (Erdogan) Mob
President Putin nailed it; it was "a shot in the back." Because all evidence is pointing towards an ambush: the F-16s might have been actually waiting for the Su-24s. With Turkish TV cameras available for maximum global impact.
Two Su-24s were getting ready to strike a bunch of "moderate rebels." Ankara says they were Turkmen -- which the Turks finance and weaponize. But there is just a small bunch of Turkmen in northern Syria.
The Su-24s were actually after Chechens and Uzbeks -- plus a few Uyghurs -- smuggled in with fake Turkish passports (Chinese intel is also on it), all of these operating in tandem with a nasty bunch of Turkish Islamo-fascists. Most of these goons transit back and forth between the CIA-weaponized Free Syrian Army (FSA) and Jabhat al-Nusra. These were the goons who machine-gunned the Russian pilots as they parachuted down after the hit on the Su-24.
Erdogan well knows how US neocons were livid with French President Francois Hollande after his "it's war" cry was followed by a drive to work together with Russia against ISIS/ISIL/Daesh.
So the real target was not a Su-24, but the evolving possibility, after the Paris attacks, of a real coalition -- the US, Britain and France on one side, the "4+1" (Russia, Syria, Iran, Iraq plus Hezbollah) on the other side -- finally converging their interests into a unified fight against ISIS/ISIL/Daesh.
Where would that leave Ankara, which for years has invested heavily in the Salafi-jihadi nebulae, from Jabhat al-Nusra to Ahrar al-Sham and myriad other outfits, culminating with aiding and abetting and even funding ISIS/ISIL/Daesh?
Turkey, for all practical purposes, has been a handy, sprawling Salafi-jihadi Infrastructure and Logistics Center; it offers everything from porous borders enabling countless jihadi return tickets from Syria to Europe, facilitated by corrupt police, to a convenient crossroads for all kinds of smuggling and a hefty money laundering ops.
So Ankara, with a missile, thought it might completely change the narrative.
Hardly. Just follow the money. Even in the US and Europe the Turkish game is becoming increasingly transparent. A research paper at Columbia University details at least a fraction of the multiple instances of collusion between Turkey and ISIS/ISIL/Daesh.