Any ideology that continually promotes and commits terrorist attacks is a dangerous ideology and needs to be controlled. Islam is the clear #1 on that list, and it's not even close.
Guys like Timothy McVeigh were not part of something bigger so there's nothing really to do about it.
It's a one-time attack you hope to prevent, but if you don't then that's the end of it.
That's the scary part about Islam, is that it just never ends.