"The problem is this war, unlike wars in the past, has no apparent limit of duration.
That's plain wrong. No war has had a fixed time limit, yet."
True. But the general understanding has been that wars would be of a fairly limited time. Not always true, of course. The French and British fought something called the Hundred Years War, though I don't know much about it and can't say how much it was like a continuous war for a hundred years. But there is an implication behind the idea of suspending our rights as Americans for the duration of the war---the implication that the war will not last for decades.
Fighting a war that apparently will last for decades is a different situation than most wars.
Pardon my curiosity, but what rights have you had suspended for the duration?