NEW YORK — If it happens, the trial of Khalid Sheik Mohammed will make for riveting drama amid the dry routines of procedure in federal court. Of all the many risks in the contest, the greatest may be the drama itself.

In the narrowest of legal terms, the case against Mohammed — self-proclaimed author of the Sept. 11, 2001 attacks — and four co-defendants is about particulars of fact and law: deliberation and intent, deed and consequence, guilt and innocence. Attorney General Eric Holder said on PBS's "NewsHour" that "this is not a show trial," but both sides hope to use the case to define Sept. 11 as a parable of right and wrong.

Prosecution and defense will fight for control of a narrative that is sure to reach hundreds of millions of people. The verdicts drawn around the world may inspire or dismay potential allies, provoke or deter action, and in the end advance or impede the starkly opposing interests of the United States and its radical Islamist foes.

Part of the Obama administration's message is a symbolic break with the most controversial policies of President George W. Bush. Where Bush used the U.S. military prison at Guantanamo Bay, Cuba, as a fortress against domestic and international law, President Barack Obama is bringing the Sept. 11 defendants into independent constitutional courts.

But Friday's announcement that the cases of Mohammed and four other accused Sept. 11 plotters would be tried in civilian court brought no broad departure from Bush's legal bequest. Holder and Obama have only gradually shifted course from "never" to "hardly ever" in granting Guantanamo Bay detainees access to what the attorney general described as a 200-year tradition of "faithful adherence to the rule of law" in the judicial branch.

Bush allowed more than 800 terrorism indictments to be handed up by federal grand juries, resisting constitutional protections only for those he declared to be "unlawful enemy combatants." The Obama administration has granted such rights to six of the 241 detainees who were at Guantanamo Bay when the president took office, and senior government lawyers have said there is next to no prospect of bringing more than 20 more to trial in any tribunal, civilian or military.

Obama is acknowledging explicitly, as Bush never did, that some defendants will enjoy more legal protection than others, that their rights in military commissions will be inferior to those enjoyed by the few who reach federal court.