"How far back do you want to take the route cause." As far as...

"How far back do you want to take the route cause."

As far as necessary to try and understand the question at hand.

"Pretty simple everyone admits the syrians shot down the russian plane."
"Syrian incompetence."

Or Israeli skulduggery.

I see a catastrophe developing in the ME due to the attempt by the US to use its military superiority to overcome an historic decline in their world economic position vis a vis their rivals Japan and Europe and more lately Russia and China. (not that all those countries don't have their own economic crisis)
That was signaled by the invasion of Afghanistan and Iraq.

Therefore the US is the most aggressive and destabilizing factor in world affairs and particularly in the ME, no matter who happens to be President or which party has a majority.