FORT LEWIS, Wash. — The judge trying the first U.S. officer court-martialed for refusing to ship out for Iraq barred several experts in international and constitutional law from testifying about the legality of the war.

First Lt. Ehren Watada, 28, of Honolulu, is charged with missing movement for refusing to ship out with his unit. He also faces charges of conduct unbecoming an officer for accusing the Army of war crimes and denouncing the administration for conducting an "illegal war" founded on "lies."

As his court-martial began, military judge Lt. Col. John Head refused to allow almost all defense witnesses to take the stand. Head previously ruled that Watada's attorney, Eric Seitz, could not debate the legality of the Iraq war in court.

If convicted, Watada could receive four years in prison and a dishonorable discharge. He has requested that his case be heard by a military panel of officers, the equivalent of a jury.

The defense and prosecution questioned a pool of 10 officers. Seven were ultimately chosen to sit on the jury.

Today, prosecutors are expected to call at least three witnesses as they try to prove that Watada's speech amounted to misconduct.

Many of the facts are not in dispute. Watada admitted yesterday that he ignored an order to board the June flight that carried his unit, the 3rd Brigade, 2nd Infantry Division, to Iraq for a yearlong deployment.

"My intent was to refuse the order, sir," Watada told Head.

He also admitted criticizing the Bush administration's handling of the war, which he has called "morally wrong" and "a horrible breach of American law."

Seitz said he would call Watada and a character witness, an Army captain who has known Watada for about two years. The captain has been brought back from service in Iraq to testify, the lawyer said.

Watada is the first officer to publicly refuse deployment to Iraq and face court-martial. Army Sgt. Kevin Benderman, an enlisted man, served 13 months in prison and was dishonorably discharged after refusing to go to Iraq in 2005.

Outside the base, a small group that included actor Sean Penn demonstrated in support of Watada. A few others demonstrated against him, including one man who carried a sign calling Watada a "weasel."

Army prosecutors have argued that Watada's behavior was dangerous to the mission and morale of soldiers in Iraq.

"He betrayed his fellow soldiers who are now serving in Iraq," Capt. Dan Kuecker said at one hearing.

Seitz said yesterday that rulings that went against his client in pre-trial motions, including the exclusion of many defense witnesses, rendered the proceedings "almost comical" and at one point called the case "an atrocity."

Seitz had hoped to debate the legality of the war and planned to call constitutional law scholars, a CIA analyst and a former undersecretary of the United Nations, among other witnesses.

"There's really nothing for us to say in this courtroom," he said.

Head told Seitz to "leave the dramatics at the courtroom door."

Representatives from more than 30 media outlets covered the trial — including television stations from Japan and Germany.

The Associated Press and The News Tribune of Tacoma, Wash., contributed to this report.