The root of Islamic fundamentalist terrorism is Muslim fundamentalism!
You can kill all the terrorists you want, but until you destroy the terrorist mill of extreme Islamic fundamentalism, you've done little more than nothing.
Russia's actions in those countries they're still trying to hold on to in the aftermath of the fall of the USSR, are at the root of the growth of terrorism in that area, and the opening Islamic extremism needed to penetrate the region.
The primary site of the tumor is in Mecca.