I don't know man but if Iran and Russia wages a war anytime, it must be pretty soon enough for us to see it. Yet I just don't see the entire world battling with each other anymore after the experience of WW II. They've learned to waste lives of other nations in sake of their interests rather than fellow countrymen's lives.
I think they try to avoid it as well. The problem is that at a certain point you are cornered by your alliances.
Let us ssay that Syrian forces attack the rebels on Turkeys soil and some Turkey troops die defending their territory. Turkey can invoke Article 5 of the NATO pact.
That means Albania, Belgium, Bulgaria, Canada, Croatia, Czech Repub, Denmark, Estonia, France, Germany, Greece, Hungary, Iceland, Italy, Latvia, Lithuania, Luxembourg, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, United Kingdom (Britain, Wales, Scotland & Ireland) and the United States (Turkey is excluded in this scenario) are treaty bound to treat it as an attack on them directly.
So do you honor your pact (I think they are duty bound to keep their word) or do you break your word and leave those other 27 countries (28 country members of NATO) without your aid? if you break your word how likely are they to trust you on something down the line?
Edit: As Revo said it is very dangerous ground.