There is no question that there are many evil people in the world who would love to attack America and given the chance they will do so. Many of the actions taken under the Bush administration have worked quite well in keeping such people out of our fair land. I give him credit for that. However, I doubt that his extreme tactics, the use of torture and ignoring constitutional principles in dealing with suspected enemies, has had a causal relationship to protecting America from attack. John McCain, who has firsthand knowledge of the use of torture, has expressed that same opinion.
Information extracted under physical duress is highly unreliable. Under even minimal levels of torture, people will confess to what ever their interrogators want them to. As far as incarcerating suspected enemies for long periods of time without any due process of law, the founders of our republic specifically wrote protections into the Constitution from such actions. They were reacting to just that kind of policy on the part of our colonial masters at the time. Thus, the imprisonment of suspected enemies at the Guantanamo base in Cuba is antithetical to the core principles of the American nation. We certainly can keep our nation safe without violating our basic beliefs.
Unfortunately, conservatives have interpreted such statements as being soft on terrorism. It is true that brutal dictators have been quite effective in protecting their realm from terrorists. However, do we want America to sink to that level? I think not. The founders of our republic wrote into the Constitution methods for determining who is guilty and who is not. From my perspective, as much as possible, we should stick to the Constitution.