Not surprisingly, there’s great sympathy in America for hunting down terrorists, convicting them of their crimes, and meting out heavy-duty punishment. I share those objectives. Indeed, if I had Osama bin Laden in my crosshairs, I would gladly pull the trigger. That said, I also have great sympathy for the Constitution, which safeguards the personal liberties that sustain a free society, like the right to due process. The Bill of Rights, after all, is more than scrap paper. And it applies to “persons,” not just U.S. citizens.

That’s one reason why President George W. Bush’s most recent executive order about military tribunals is so troublesome. The president has declared an “extraordinary emergency,” which supposedly empowers him to order military trials of non‑U.S. citizens — even if they are arrested here, are tried here, and reside here legally. Bush need only assert that he has “reason to believe” the non-citizen is involved in international terrorism intended to have “adverse effects on the United States, its citizens, national security, foreign policy or economy.” Presto, the suspect’s constitutional rights vanish, along with our 200-year tradition of respect for the rule of law. Sorry, but we must have different rules for legal aliens who are arrested in the United States. For them, a military tribunal is truly unamerican.

Here’s how the new executive order works: The president ordains who will be tried by the military tribunals. Then Defense Secretary Donald H. Rumsfeld appoints a panel to decide the case. He sets the rules, including how many members will be on the panel, what qualifications they must meet, what standard of proof will be needed to convict, and what type of evidence can be considered. There will be no judicial review. Only Bush or Rumsfeld will have authority to overturn a decision.

That’s law on the fly: Secret trials, unilaterally decreed by the executive branch, without judicial affirmation that secrecy is necessary; due process, turned on its head, renouncing the values that distinguish us from the fanatics we seek to punish. Astonishingly, the only rule that Bush’s executive order lays out with specificity is that the accused can be convicted and sentenced — to life in prison or death — if two thirds of the panel agree.

Even military courts, under the Uniform Code of Military Justice (UCMJ), require unanimity in capital cases and provide for several stages of appellate review. They also preserve many of our Fifth Amendment rights, like protection against double jeopardy and self-incrimination, and the right to Miranda-type warnings. Unlike conventional military courts, the new Bush tribunals could unleash an ugly and dangerous breed of justice, lacking civil liberties guarantees that even the UCMJ affords. That regime might be imposed on legally resident non-citizens. Yet the U.S. Supreme Court has applied the same strict scrutiny to discrimination by citizenship that it applies to discrimination by race.

Moreover, if the new regime is invoked for acts already committed, and it reduces evidentiary standards needed for conviction — as surely could happen under the Bush directive — then it will violate the constitutional ban on ex post facto laws. That’s not all. There are several other loosely-worded, scary clauses in the executive order. For example, the secretary of defense can “transfer to a governmental authority control of any individual” under the order. That could easily be construed to condone deportation, without conviction or trial, to a country that would be more willing than the United States to extract information by torture. The order also provides that a detainee “shall not be privileged to seek any remedy … directly or indirectly … in any court of the United States.” Despite denials from the Bush Administration, that provision sounds much like suspension of habeas corpus — long celebrated as the “Great Writ.” Yes, if Congress approves, habeas can be suspended, but only if there has been an invasion or rebellion, neither of which is a fair characterization of September’s horrific acts by a handful of crazed radicals.

Once an individual is scheduled to be tried by a Bush tribunal, the tribunal secures “exclusive jurisdiction with respect to offenses by the individual.” Note that the executive order says “offenses,” not “terrorism offenses.” Thus the tribunal might acquire authority to prosecute ordinary crimes — like, say, drug dealing — as long as the president had “reason to believe,” although not much evidence, that the defendant was also involved in terrorism. That would not pass constitutional muster. In Ex parte Milligan (1866), the Supreme Court held that military tribunals may not try civilians unless the civil courts are “actually closed and it is impossible to administer criminal justice.” More recently, after Pearl Harbor, Hawaiian authorities declared martial law, closed the civil courts, and used military tribunals to prosecute ordinary crimes. Five years later, in Duncan v. Kahanamoku (1946), the Supreme Court reaffirmed that martial law could not justify replacing civil courts with military tribunals.

Significantly, the Court also held in Ex parte Milligan that martial law may be declared only by Congress, during wartime, and subject to judicial review. That raises another grave problem with the Bush edict: The entire scheme was concocted without congressional input. Citing his power as commander in chief, Bush claims unilateral authority to establish the new tribunals. But that authority, at best, is shared with the legislative branch. Congress, not the president, is empowered by Article I, section 8, “To make Rules for the Government and Regulation of the land and naval forces.” The administration has two responses.

First, it contends that Congress has spoken. On Sept. 14, the Senate and House overwhelmingly passed a resolution authorizing “action against those nations, organizations or persons” that the president determines “planned, authorized, committed or aided” the terrorist attacks of Sept. 11. True enough, but the resolution had nothing to say about tribunals. It sanctioned the use of force, not the procedures for convicting guilty parties. Second, the administration cites the secret military trial, ordered by Franklin Roosevelt, of eight Nazi saboteurs who had landed in the United States with explosives. In 1942, the Supreme Court gave its consent (Ex parte Quirin), and six of the eight were ultimately executed. Yet that case cuts the other way. For starters, it applied to agents of a foreign government who were in this country illegally. Moreover, the Court upheld the right of judicial review, which is nowhere to be found in the Bush executive order; and observed that Congress had formally declared war, expressly authorizing military trials of offenses “against the law of war.”

The Bush executive order takes a perilous step toward eviscerating the time-honored doctrine of separation of powers, a centerpiece of our Constitution. Too much unchecked power is vested in a single branch of government. The president and his secretary of defense — if not this administration, then a successor with fewer constitutional scruples — can run roughshod over the Bill of Rights. At a minimum, to the extent that military tribunals can try legal aliens, without congressional authorization, that’s bad law, bad public policy, and morally indefensible. This decent and honorable president can do much better.