Absolutely. Our absence will remove their raison d'etre.
I'm sure many, who have acquired a taste for adventure, will find will find other mischief to be up to. The Arab world has tens of thousands of unemployed, disaffected youth seeking a place and purpose in life, and a long history of conflict -- internal and external. But if we don't impinge ourselves on their lives they won't bother themselves with ours.
I think a reminder of what the Taleban (meaning student) are and what they believe is:
From Wiki but there are many sources,the ideas are Sayyid Qutbs
The way to bring about this freedom was for a revolutionary vanguard [36] to fight jahiliyyah with a twofold approach: preaching, and abolishing the organizations and authorities of the Jahili system by "physical power and Jihad."
The vanguard movement would grow with preaching and jihad until it formed a truly Islamic community, then spread throughout the Islamic homeland and finally throughout the entire world, attaining leadership of humanity. While those who had been "defeated by the attacks of the treacherous Orientalists!" might define jihad "narrowly" as defensive, Islamically-correct Jihad (according to Qutb) was in fact offensive.
So as we can see they have no intention of ambling back to the hills at all,and i cannot see how anyone can believe they will.