In a bad-case scenario, let's say that Swedes decide they hate America, start infiltrating, and suicide-bomb the shit out of all Ikeas and Waffle Houses. By the time all Ikeas and Waffle Houses are toasted, the Swedes are ready to move on to new targets, and we realize that we need to start fighting back.
If the bombing starts having a permanent impact on our economy and way of life, and killing thousands of Americans a week, and is getting worse not better, do you really think we shouldn't consider bringing in Swedes and holding them for questioning over extended periods of time without evidence? Do you really think the first trial of a Swede terrorist should take place in the public court system where security is poor and we are likely to lose valuable intelligence secrets to the enemy in the process of conviction?
I can't imagine you've thought this through completely if you've arrived at the conclusion you seem to have arrived at. Would you really allow a nation to be destroyed in order to preserve its liberties? And do you REALLY think this is a PERMANENT war on terrorism, especially considering that it's about three months old now?