Two Malaysian prisoners at Guantánamo Bay pleaded guilty on Tuesday to conspiring in the October 2002 nightclub bombings in the resort island of Bali, Indonesia, that killed more than 200 people.
The guilty pleas were the first step in a slowly unfolding proceeding that began when the men, Mohammed Farik Bin Amin, 48, and Mohammed Nazir Bin Lep, 47, were charged in 2021 — 18 years after their capture in Thailand. Sentencing is scheduled for next week.
The pleas were also seen as a breakthrough for military commission prosecutors, who had been seeking deals to resolve long-running cases against former C.I.A. prisoners. Similar talks with the accused plotters of the attacks of Sept. 11, 2001, ended last year after the Biden administration declined to consider health care and confinement conditions sought by the prisoners.
Both defendants were held for years in the C.I.A.’s secret overseas prison network. They were transferred to Guantánamo Bay in 2006 for trial at the special national-security court that President George W. Bush set up after the Sept. 11 attacks. While in agency custody, according to their lawyers, they were tortured, along with their accused ringleader Encep Nurjaman, an Indonesian prisoner known as Hambali.
In pleading guilty, Mr. Bin Amin and Mr. Bin Lep agreed to testify against Mr. Hambali, the former leader of the Jemaah Islamiyah movement, an affiliate of Al Qaeda in Southeast Asia. The charges cast them as Mr. Hambali’s lieutenants or foot soldiers whom he recruited to take part in never-realized suicide bombings of U.S. targets.
Depending on what testimony they provide, prosecutors may be spared the need to use statements made by Mr. Hambali after he was tortured by the C.I.A. The question of whether confessions prisoners made after years of C.I.A. detention are tainted by torture has stalled efforts to begin the Sept. 11 and U.S.S. Cole bombing trials for more than a decade.
Both prisoners wore traditional tunics and trousers to court and sat mostly silently in court listening to the proceedings through Malay translation. Their lawyers entered guilty pleas on their behalf.
Absent from the pleas was any link to the car bombing of a Marriott hotel in Jakarta in August 2003 that killed 11 people, for which they were originally charged. Prosecutors also dropped charges of terrorism, attacking civilian and civilian objects and attempted murder as part of the plea deal.
While little noted in the United States, the suicide bombings of Paddy’s Pub and the Sari Club in the island resort on Oct. 12, 2002, is still a painful memory in Australia and Indonesia, which suffered most of the casualties.
Much of the day was devoted to detailed questioning by the military judge about whether they were voluntarily admitting to conspiring with Mr. Hambali, Osama bin Laden and others to murder and maim workers and vacationers through bombings of the two popular social spots. The charge sheet listed the 202 people from 22 nations who died that day, seven of them Americans.
The judge, Lt. Col. Wesley A. Braun of the Air Force, also stressed to the defendants that, although they may not have personally carried out the bombings, they were admitting to being criminally responsible as members of an unlawful conspiracy.
As part of the plea, the defendants agreed to a narrative describing their relationship to Al Qaeda and the Jemaah Islamiyah movement, and how, they said, Mr. Hambali encouraged them to go to Afghanistan for firearms and basic military training with Al Qaeda in 2000.
There, in late 2001, Mr. Hambali chose them to take part in a never-realized suicide attack against the United States, called a martyrdom operation. They also swore an oath of allegiance to bin Laden, a key component making them conspirators.
In their plea, they do not say they knew about or took part in the Bali bombing. But they agreed that they had returned to Southeast Asia by early 2002 and knew that Mr. Hambali was a wanted man both before and after the bombing, and helped him elude capture.
Family members of people killed at Bali arrive at Guantánamo Bay this weekend from the United States as well as possibly from Australia, Britain and Germany for the sentencing phase. Jurors will be brought to the base next week to decide a less-than-life sentence.
Neither the narrative nor the pretrial agreement the men reached with prosecutors and a senior Pentagon official last year have been made public to shield that information from the military jury. At Guantánamo, they have typically included a sentencing range the jury may consider and, potentially, a side agreement on whether they might serve their sentences in their homeland.
Under the pretrial deal, they will provide sworn testimony against Mr. Hambali in the event they are repatriated to Malaysia to serve their sentences, and not available to testify at Mr. Hambali’s trial. Prosecutors have proposed a 2025 trial date.
Prosecutors were expected to take the testimony through depositions this weekend, with Mr. Hambali’s legal team taking part.