FORT MEADE, Md. - Government secrecy reaches a new level this week in the court-martial of Army Pfc. Bradley Manning, an intelligence analyst who sent 700,000 classified U.S. documents to the WikiLeaks website.

A military judge, Col. Denise Lind, has ordered what prosecutors say is an unprecedented closed hearing Wednesday at Fort Meade to help her decide how much of Manning's coming trial should be closed to protect national security.

An unidentified prosecution witness will testify during that closed hearing in a "dry run." Defense attorneys say that could allow the judge to find ways to avoid closing the courtroom to the public during the presentation of classified evidence.

Lind and attorneys for both sides have suggested there are a number of options to shield sensitive material, including closing parts of the trial; redacting documents; using written summaries as evidence to omit sensitive details; or even using code words for classified information.

The sensitive evidence includes Iraq and Afghanistan battlefield reports and State Department cables Manning has acknowledged leaking, along with official communications about those classified documents. The government says the leaks in 2009 and 2010 endangered lives and security. Manning's lawyers contend there was little to no damage.

Lind's decision to hold the practice run out of public view has drawn mixed reactions from national security and legal experts. Air Force Reserve Lt. Col. David Frakt, who teaches at the University of Pittsburgh law school, called it a "great idea" for minimizing disruptions such as those at U.S. military commissions' cases involving terrorism detainees at Guantanamo Bay, Cuba. Frakt defended Guantanamo detainees Mohammed Jawad and Ali Hamza al Bahlul in 2008 and 2009.

"The judge wants the trial, when it happens, to go smoothly, and the last thing you want is some inadvertent disclosure," Frakt said.

But Jesselyn Radack, national security and human rights director of the Washington-based Government Accountability Project, said there has already been too much secrecy in the Manning case.