An excerpt from, "Turkish promise to ‘defend’ Aleppo may lead to direct conflict with Russia" by Mikhail Moshkin, Andrei Reznikov, Vzglyad, Russia Beyond The Headlines, February 11, 2016:
Konstantin Sivkov, vice president of the Moscow-based Academy of Geopolitical Problems, believes that Turkey is capable, if nothing else, of providing air support for Assad's opponents. This would become a problem for Russia, which would then find it necessary to repel such strikes and unleash an attack on the Turkish air force.
"But the Turks are also very capable of starting a ground operation, which according to international law, will be considered an act of aggression against Syria," explained Sivkov.
In his words, this would result in a war with Russia, forcing NATO to decide whether or not to side with Turkey. Such a scenario will raise the question of NATO being involved in a direct military clash with Russia, which possesses a nuclear arsenal.
Retired Colonel Viktor Murakhovsky, a military expert and editor-in-chief of the military magazine Arsenal Otechestva, insists that any Turkish incursion into Syrian territory will be an act of aggression. Consequently, the UN Security Council will be forced to convene immediately, with Russia and China bound to take a firm stance against such a development.
"Concerning the Russian air force, we are not fighting with Turkey. It will be the official Syrian government to decide what to do in this case, how to counter such an act," said Murakhovsky.