A public trial of Mohammed in downtown Manhattan would challenge virtually every component of the U.S. legal and political system. It would have immense historical and diplomatic significance. But although the conclusion is relatively sure -- few seriously following Mohammed's legal tangle believe that he would be acquitted -- the manner in which his story will unfold from here remains a genuine mystery. For example, a civilian trial for Mohammed would test the government's ability to introduce classified terror-related evidence to jurors in a case directly involving the 9/11 attacks. The proceedings also could belatedly test the legal boundaries of the government's 'enhanced interrogation techniques,' which purportedly were used on the defendant. Nearly seven years of Bush administration military commissions have given us little more than a giant legal headache. No matter how bad it tastes going down, the dramatically styled case, United States vs. Mohammed, would be the cure. A Mohammed trial in the heart of New York also would be an immense test of whichever trial court judge happens to hear it. With the world's attention on her or him, that judge would have to sift through novel detainee arguments, curb prejudicial pretrial publicity, control the defendant and ultimately render a proceeding worthy of our fealty to the Constitution. No judge in modern American history has faced such a challenge. The Mohammed trial would be a deep challenge to his lawyers as well. If he doesn't succeed in firing them, which he already has tried to do, Mohammed's court-appointed attorneys would be caught between their client's extremist views, ambiguous legal precedent and the righteousness of the federal prosecutors. For Team Mohammed, it's really a no-win situation: How to represent in a capital case arguably the most vilified man to be brought to trial in the United States. The proceedings also would test the defendant himself. Mohammed already has made it clear he has plenty to say. Would he boast of his work for al-Qaida? Would he complain about his confinement since his capture in 2003? What would it be like for New Yorkers when Mohammed speaks just a few blocks from where the World Trade Center stood? What would it have been like for Oklahomans if Timothy McVeigh had been allowed to stand in the dock down the street from the Alfred P. Murrah Federal Building? A trial for the once-upon-a-time 'face of terror' also would challenge the media, especially New York's local media. The O.J. Simpson trial could seem like a high school play compared with the coverage the Mohammed trial might generate. Would the lack of live, in-court television coverage curb the inherent sensationalism of the event? The U.S. criminal justice system has not yet been truly tested in the age of Twitter and Facebook and iPhones. This case would be that test. Finally, the Mohammed trial would be a test for all the rest of us. Could this nation, less than a decade after the worst attack on its soil since Pearl Harbor, ensure a semblance of a fair trial for one of the most important men accused of being responsible for that attack? Would we have the strength to show confidence in our rule of law? Or would we tacitly agree that whatever sort of justice he gets at whatever sort of trial would be more than what he deserves? The Mohammed trial would be a battle between constitutional philosophies, political and military practicalities and prejudices, and human hearts and minds. I've covered every major trial in the United States over the past 13 years. This one has the elements and the potential to dwarf them all. Cohen is CBS News' chief legal analyst and legal editor. 