That is an interesting question, LD. The Pope has described this terrorism as part of a "piecemeal third world war." http://www.huffingtonpost.com/entry/pope-francis-world-war-3_5648ab7de4b06037734973e6
Lorne, it may be a "piecemeal third world war," after what happened in Paris, but what bothers me most is the presence of the US and Russia in Syria. Any accidental confrontation between these two may bring dangerous results.
I can see large swathes of the Muslim Middle East being transformed into a dystopian wasteland, LD, but it's unclear that the major powers would go to all out war over it because it's simply not worth it. If it's a major war you worry about, focus on the South China Sea.
Mound, you make interesting points. As I pointed out to Lorne, the worrisome part is the presence of both Russia and the US in Syria. I hope these two world powers are careful and don't set off any kind of spark which may get them involved with each other. That will bring dangerous consequences.