WASHINGTON - The Defense Department, under pressure from Congress to reexamine the way it handles sexual-assault cases, announced Tuesday a comprehensive review of the entire military justice system.

"It's been over 30 years since the military code of justice was reviewed. It's simply time," said Lt. Col. J. Todd Breasseale, a Pentagon spokesman. "Sexual assault will certainly be part of the compendium of issues that will be looked at, but it's by no means the sole issue."

Members of Congress and women's groups have been critical of how the military handles sexual-assault cases, particularly the authority that military officers have to overturn the convictions of those under their command. A proposal by Sen. Kirsten Gillibrand (D., N.Y.) to remove the chain of command from authority over cases involving major crimes was blocked last month by a filibuster.

She was critical of the military's move to review its justice system, noting that the panel would take a year and a half to complete its work. She said solutions were obvious now.

"We can do review after review after review - and I have no doubt they are all well-intentioned," she said in a statement. "But according to the DOD's latest available numbers, 18 months is another estimated 39,000 cases of unwanted sexual contact that will occur."

Military prosecutors have recently struggled with several high-profile sexual-assault cases.

Eugene Fidell, who teaches military justice at Yale University, said the review was probably prompted by the controversy over adjudication of sexual assaults in the military but that its scope would be much broader. "As I understand it, it will be a top-to-bottom review, which means everything is on the table," he said.

The review panel will be headed by Andrew Effron, the recently retired chief judge of the U.S. Court of Appeals for the Armed Forces, and will include lawyers from all the military services. Judge David Sentelle, a noted conservative on the U.S. Court of Appeals for the D.C. Circuit, and Judith Miller, a former Defense Department general counsel under President Bill Clinton, will serve as advisers.