“The probability is close to 1 that Daesh/ISIL will destroy them.”
A great deal has been destroyed over the centuries in that region, and a lot has been preserved.
Who EXACTLY is DAESH/ISIL for the latest destruction? No one seems to know.
But I see a few guarantee those who brought DAESH around, will be eventually destroyed by the same (DAESH).
You have some info here
https://kyleorton1991.wordpress.com/2015/12/23/how-saddam-hussein-gave-us-isis/
and here http://freerepublic.com/tag/by:admsmith/index?tab=comments;brevity=full;options=no-change