WASHINGTON – A military judge ordered yesterday an Army general who commanded the detention center at Guantanamo Bay to testify at the court martial of a dog handler in the Abu Ghraib prison scandal.

The judge, Marine Lieutenant Colonel Paul McConnell, agreed to allow attorneys to question Major General Geoffrey Miller during the trial of Sergeant Santos Cardona, who is accused of using his dog to abuse inmates at Abu Ghraib in Iraq.

General Miller would become the highest-ranking military officer to testify in the Abu Ghraib scandal. Early this year, General Miller said he was refusing to answer questions, but he is prepared to testify now, Sergeant Cardona’s lawyer said.

Colonel McConnell rejected a request from Sergeant Cardona’s lawyers to summon Defense Secretary Rumsfeld to testify at the trial.

General Miller was sent to Abu Ghraib by Mr. Rumsfeld in late summer of 2003 as the Iraqi insurgency began to gain momentum. Cardona’s lawyers say the general has valuable testimony about the interrogation techniques that led to prisoner abuse.

General Miller was commander of the detention center at Guantanamo Bay, Cuba, when he was dispatched to the Abu Ghraib prison as the American military desperately sought intelligence from prisoners in an effort to stamp out a growing insurgency.

Sergeant Cardona, a 31-year-old soldier from Fullerton, Calif., is scheduled to go on trial next month. He faces charges of maltreatment of detainees and dereliction of duty.

A month ago, another Army dog handler at Abu Ghraib, Sergeant Michael Smith, 24, of Fort Lauderdale, Fla., received six months behind bars for using his snarling dog to torment Iraqi prisoners. Sergeants Smith and Cardona worked together.

The Abu Ghraib prison scandal erupted during the presidential campaign in the spring of 2004 when photographs of the abuse were leaked to the news media.

Nine other soldiers have been convicted of abusing prisoners at Abu Ghraib. Critics have called for an outside investigation into whether high ranking military officers and civilian Defense Department officials condoned abuse at the prison.

General Miller is the former commander of the detention center at Guantanamo Bay, Cuba, who led an assessment team to Abu Ghraib in early September He later was put in charge of the Abu Ghraib prison.

In January, General Miller invoked the military’s version of the Fifth Amendment right to not incriminate himself.

Dog teams were sent to Abu Ghraib in November 2003 on General Miller’s recommendation.

General Miller’s account conflicts with that of Colonel Thomas Pappas, the former top-ranking intelligence officer at Abu Ghraib.

General Miller has said he recommended in 2003 that dogs be used for detainee custody and control, but not for interrogations. Colonel Pappas, however, told investigators that General Miller told him dogs had been useful at Guantanamo Bay in setting the atmosphere for interrogations.

The alleged mistreatment of prisoners at Abu Ghraib occurred in late 2003 and early 2004, when military interrogators were under tremendous pressure from superiors to gather intelligence in an effort to stamp out the spreading insurgency in Iraq.