Now and then something like this happens. That is, someone shoots down an airplane that they think is trespassing or is some kind of a threat to them. The US Navy, for instance, shot down an Iranian airliner on one occasion...presumably mistook it for something dangerous?

Such an incident only results in a war between nations when people on one or both sides completely lose their heads....

or...

When someone wanted a handy excuse for launching that war in the first place, in which case the incident serves the purpose.

I doubt that the Turks want such a war. I doubt that the Syrians want such a war. Why would they? Others in the international community may, however, want such a war for their own reasons, if they think it serves their strategic purposes.

The smart thing for both the Turks and the Syrians to do in this case is not completely lose their heads over the incident. You cannot cure the initial problem of losing one airplane and 2 men by starting a war that destroys a vastly greater number of other machines and human beings just to show everyone how VERY upset you are about losing that first airplane.

But if you're a fool or a lunatic...well, then you might try to cure the problem in that fashion.