The terrorists are stupid in many respects, uniting the US and Russia in their fight against them is one.
However, terrorism exists because it is so easy. Anyone willing and stupid enough to die can do it, and can do it wherever and whenever there is a chance. I don't see it going away soon.
How did we get the Japanese to surrender? They had a similar "we'll rule the world or die trying" religion.
They are our friends now -- those who were the children of what few remained alive.