Let's pick a name at random. It need not be a real person for the sake of this example. Let's call the guy "Al."
Al is a U.S. born American citizen who at some point finds Islam. He later embraces Islam and one of its most radical sects. He becomes a militant. Al grows to hate the U.S.A. with a burning passion. Who cares why?
Al joins al qaeda. Al advances in al qaeda. His career path takes him into the upper echelon of al qaeda. There, with others of similar ilk, he actively plans and plots to attack America and Americans and American interest with deadly force.
The U.S. military and intelligence forces "find" the guy and intercept some of his communications and come to the realization that he is actively planning some imminent attack against some of our military forces. We happen to be at war with al qaeda and they certainly consider themselves to be at war with us.
Let's get down to it. What is the U.S. military supposed to do with this intel?
Is it actually the case that the military, the President and his Administration, is obliged to submit the evidence against "Al" to some robed person in the Judicial Branch? Why?
Let's say that out of an abundance of caution, that is the path the President chooses to take. He goes to some Court (possibly doing it on a secret basis, like back in chambers with a sealed record?) and lays out the intel. No cross examination? No right of Al to be heard? Or maybe there must be? That would kind of blow the State Secret out of the water, wouldn't it?
For now let's say that it is not the "kind" of judicial proceeding that Al has to be invited to participate in. But even without a defense attorney speaking for his side, the Judge concludes that the intel is too sketchy. Maybe he's right, but maybe he's just got his head up his ass. The point is, who gave any judge a say in how the President conducts the war?
Is the President now BOUND to do nothing? Hm. What does "Al" now do? Left to his own devices, he proceeds with his plot and the orders go out and in some way that the intel had not yet scoped out, he and his "troops" commit his planned attack. Lots of dead Americans. But, THANK GOD, the notion of "due process" has been revered and all.
Right?