Your question is framed as an either/or proposition--in other words, if we achieve one, we'll necessarily lose the other. That's just not the case, as previous posters have suggested. Our freedoms already have some limits and restrictions; to place a few more restrictions on our freedoms is probably a fair trade-off for national security. I wish I could believe that all the inconveniences at the airport, for example, have had a direct correlation to the fact that we haven't had a national incident since they were enacted, but I'm just not convinced. Until I can be sure, though, I'm willing to show up an hour ahead of time, put my liquids in a baggie, and take off my shoes.
Some freedoms have to be sacrificed for the sake of safety. For example, it is now a much longer process when traveling on an airplane because personal belongings are searched more thoroughly, etc. I do feel safer and I do not mind waiting the extra time as long as it is making my trip a safer one.
On the flip side I do feel that freedom is incredibly important and by all means we should not be willing to give up our freedoms in the name of fear. We should definitely have the right to protect and keep our freedoms but sacrificing a bit for our own safety is alright as well.
I think that it's a highly relevant question to be asked on the weekend commemoration of the September 11th Attacks. The previous thoughts were accurate. There is very little chance of anything being considered "perfect." Hence, some level of curtailing of personal freedoms is inevitable because we live in a pluralistic society. There are different realities within this where our purely personal freedoms are curtailed in the name of safety. The question ends up becoming that in the heightened zeal of pursuing the end of "national security," where is this line between what can be considered a minor infraction as opposed to a major intrusion. For example, airports might be a great venue for this. We all accept that longer lines and more questions as well as greater security measures are part of the travelling process. Yet, the notion of "random screenings" as a guise to target specific passengers or the idea that an individual is targeted might be an example of certain freedoms that should not be sacrificed in any particular name as it emboldens the state against that of the individual. The protection of national security might not be best achieved if it comes at the cost of our own national narrative of preserving individual rights.
This question is posed quite often in debates and discussion forums, but we shouldn't assume, even for purposes of discussion, that exchanging freedom actually leads to better security, or that the exchange rate involved is reasonable.
We could have absolute order in our country, secure borders, no drug trade and safety from terrorists. You could also give up your gun rights, your right to an appeal in death penalty cases, and your freedom of travel. But would you want to? One reason I do not typically favor an exchange of freedom for security is that the threat to our security is not constant or consistent, but government has a poor track record when it comes to returning our freedoms to us once the threat has been removed.
For example, al-Qaeda is a shadow of its former self, and unable to mount serious attacks anywhere near our mainland, but the Patriot Act is still in effect.
I do not think that this is a question that really lends itself to a yes or no answer. It really is something where the better question is how much should American freedoms be sacrificed.
Obviously, many of our freedoms are sacrificed every day for the sake of order. We give up various freedoms (like the freedom to speed) because exercising them might end up harming other people. This is not really any different than giving up the right to see your family off at the gate (where they actually board the airplane) in order to help (presumably) prevent terrorist attacks.
So how much freedom should we give up? I have no problem with the security checks, so long as they are actually designed to make us safer (rather than just making it look like something is being done). I, personally, would not really care if the government kept track of who I call on the phone or what I check out from the library.
But I do think that we should not go so far as to give up things like freedom of speech. We should not give up the right of habeas corpus or the right to a jury trial. These are truly fundamental rights that should not be given up in pursuit of security.