The latest controversy in the case of the alleged "twentieth highjacker," Zacharias Moussaoui, highlights why we should be using military tribunals, officially known as "military commissions," for terrorists captured during the war on terror.

Department of Justice attorneys, in attempting to satisfy exaggerated concerns about the use of such tribunals, have been valiantly attempting to try the case within our federal court system. Giving Moussaoui a fair civilian trial was supposed to "showcase" our criminal justice system and how well it works.

The effort is failing in large part because Moussaoui wants to abuse the discovery process, and is seeking intelligence from another terrorist. In their training manuals, such as one seized by authorities in Manchester, England, al-Qaeda foot soldiers are ordered, if captured, to exploit the many freedoms and protections our justice system provides. Moussaoui has certainly been doing things by the book.

The Bush administration initially raised concerns about trying the case in public courts, noting that classified information could be compromised. These concerns were validated recently. Acting as his own lawyer, Moussaoui sought to interview another suspected foot soldier of Usama bin Laden, Ramzi Binalshibh.

Justice Department lawyers said they couldn't allow two alleged terrorists to sit down to discuss their legal cases without possibly compromising classified information, destroying intelligence gathering efforts or worse. They refused to turn over Binalshibh, who is currently being detained abroad and interrogated for his self-proclaimed role in the Sept. 11 attacks. As a result of Justice's concern for national security compromises, the court may now hold the government attorneys in contempt.

In this case, the legitimate fear of compromising national security collides head on with the normal court rules governing trial preparation. This conflict between two valid concerns is exactly why the Article III courts should not be used for war on terror cases. This is one of the reasons the Constitution gives the president the authority, in appropriate cases, to convene military commissions. Congress also has formally enacted legislation to support their use through Article 21 of the Uniform Code of Military Justice.

The law establishes two pre-requisites for convening military commissions and trying individuals before them: 1) that we are in state of war, and 2) that the accused be suspected of violating the laws of armed conflict -- e.g. be war criminals. Both of these requirements are met with Moussaoui.

The United States has been in a state of war with al-Qaeda since the first attack on the World Trade Center in 1993. Since then we have engaged in attacks and counter attacks both here and overseas (some limited, some more aggressive) and remained in a state of belligerency. Further, in interviews, videotaped messages and written literature, al-Qaeda continues to claim it is conducting jihad against the United States. Therefore, we are at war, whether Congress has formally declared it or not.

The foot soldiers of al-Qaeda have clearly been involved in violating the laws of armed conflict, which prohibit the targeting of civilians -- the very thing al-Qaeda did repeatedly on Sept. 11. Moussaoui, alleged to be the twentieth highjacker who was supposed to attack either Washington or New York City, is thus subject to military commission jurisdiction.

In sum, Moussaoui is suspected of being an unlawful combatant, working on behalf of a belligerent non-state actor, who violated the law of armed conflict during a period of war. As in virtually every conflict since this nation was created, a military commission is the appropriate forum for adjudicating such a case.

The Framers were aware of the need for such courts more than 200 years ago. Let's transfer Moussaoui to Guantanamo Bay, give him a fair hearing before a military tribunal, and prevent him from further manipulating and mocking the domestic American judicial system.

Glenn Sulmasy is a professor of international law and a visiting fellow at The Heritage Foundation.