Personally, I don't like the idea of undeclared war. I think we should have declared war in Vietnam, Korea, and the Persian Gulf; and I think we should declare war now.
They do not need a declaration of war to suspend civil liberties, and even a declaration of war cannot be used to suspend civil liberties. Civil liberties can be suspended during periods of civil unrest -- riots, for example. But only those liberties relevant to maintaining control -- curfews, etc. Even under those circumstances you cannot suspend the right to trial by jury, self-incrimination, etc.
As to an "undeclared war," if we are only fighting bin Laden it is not a war. It is a use of military force to restore public safety, and hot pursuit of the perpetrators of a crime. Should any nation choose to resist these efforts, particularly if they abetted the terrorist beforehand -- that is a causi belli, and should lead to a declaration of war. But, just as the Royal Navy did not need a declaration of war to fire upon pirates, we do not need a declaration of war to use Apaches against bin Laden.
(Note that a use of force resolution by the Congress authorizing the President to use armed forces to pursue terrorists would be appropriate, and desirable.)
If we only go after bin Laden, we might as well surrender now. It is absolutely imperative that we strike against the states that sponsor terrorism. We don't have to hit them all at once; we may not have to hit them all, period, if we can put big enough frighteners on the ones we don't hit. But there are governments in this world that must be destroyed.
It is a use of military force to restore public safety, and hot pursuit of the perpetrators of a crime.
No, no, no, no. We must not treat this as a criminal act. We must not let bin Laden and his buddies get into American courts so they can hire Johnnie Cochran and Alan Dershowitz and do an OJ. And if we treat this as a crime, then that must be our goal. We don't simply kill criminals without trial.
But I want our explicit goal to be to kill bin Laden and his followers, either through military action or by execution after a quick trial before a military tribunal. That's why I want a declaration of war. So that there will be no doubt, no mixed messages, no BS about "bringing the perpetrators to justice."