If we aren't proactive in this I'm afraid there will be a much larger price to pay later.
Isn't that the reasoning the soviets used for invading Afghanistan?
My uncle was practically a communist, and he justified the invasion of Afghanistan at the end of the 70s in the same terms. The muslims were causing trouble in the soviet republics, and the Russians had to fight them on their home ground in Afghanistan.
Look how that turned out.
Too many people seem to look at it as a zero sum game. Kill X terrorists and we've won.
The problem is, the terrorists come from a pool of a billion muslims, and the more we kill, the more they recruit.
Israel has been following the same strategy for 50 years, and that fact alone should tell you something about how effective it is.