"No person shall be ... deprived of life, liberty, or property, without due process of law." Recognize that? It's a part (Amendment V) of the United States Constitution, a document that defines the form and function of the federal government. Read it again. It doesn't say "no citizen" or "no person within the borders of the United States." It says "no person."

No exceptions? Right away we start down a slippery slope. We engage in war. We deprive people of life, liberty, and property by shooting at them, taking prisoners of war, and dropping bombs. How can we justifiably do that? Well, if they're openly shooting at us, they're enemy combatants. Their "due process" is that if they act as combatants, they admit they're combatants, we can see that they're combatants, then we're entitled to shoot back at them, and they're entitled to be treated as prisoners of war if they're captured.

What if they're not openly shooting at us? Suppose there's no obvious indication that they're engaged in combat, but we think they are? Then, per Amendment V, they're entitled to a trial, for espionage, sabotage, treason, whatever. They're criminal suspects, not prisoners of war.

But now the slippery slope continues. Take a look at this memorandum from a DoD lawyer. It points out that the President took an end run around the Constitution when he persuaded Congress to authorize him to use force. Here's that resolution in full, and here's the relevant passage: "the President is authorized to use all necessary and appropriate force against those nations, organizations, or persons he determines planned, authorized, committed, or aided the terrorist attacks that occurred on September 11, 2001, or harbored such organizations or persons...."

See that? It says the President can point to a person and say "I determine that this person aided the terrorist attacks" and then that person is subject to "all necessary and appropriate force." Who determines what force is "necessary and appropriate?" It could take years for a court to decide. Obviously this part of the resolution is unconstitutional, but the writer of that memorandum won't say so.

By the way, that memorandum points out a distinction between "lawful combatants" and "unlawful combatants." You can find out more about that distinction in this article in Wikipedia, the free encyclopedia. In brief, "lawful combatants" are entitled to prisoner-of-war treatment, and "unlawful combatants" are entitled (not necessarily under international law, but under the U.S. Constitution) to a fair trial.