The president's national security aides say the advisers will be "special operators" _ military lingo for Special Operations forces. While those troops include the Army's Delta Force, Navy SEALs, and Marine Corps and Air Force units, defense experts say most, and perhaps all, of the advisers en route to Iraq will be Army Green Berets, because of their expertise in training foreign fighters.

"These special operators will be advisers, but they will be with Iraqi units, and if those units get engaged by the enemy, they will defend themselves," said Fred Wellman, a former Army lieutenant colonel who served as spokesman for Gen. David Petraeus when he commanded U.S. and allied troops in Iraq.