It is true that many libertarians do have doubts about those things. But even those of us who approve of wartime actions against terrorism should always have "doubts" when it comes to the poissible revocation of our precious and hard-won civil liberties in this country. To do otherwise would be folly and failure to learn form the lessons of history.
But you are glossing over the fact that many libs are members of the "hate America" crowd, just like Chomsky, et al. They fail to acknowledge that America, with all its faults is still the best country in the world and in fact the best country in human history.