Mr. Noordin was a charismatic, university-educated Malaysian who moved to Indonesia in 2002. There he built bombs, trained young recruits, and helped organize attacks on Western targets. These included the bombing of the JW Marriott hotel in Jakarta in 2003, an attack in 2004 on the Australian Embassy, and, most recently, suicide bombings at the JW Marriott and Ritz-Carlton hotels on July 17.
Authorities said he died Thursday in an overnight police raid on a safe house in central Java, along with two accomplices. His death came one month after police killed a militant linked to the July 17 bombings who was mistakenly identified as Noordin. Police said this time they had matched his fingerprints.
Noordin taxed authorities with his ability to evade police dragnets, switch operational tactics, and seed new terror cells. While others are certain to try to take his place, they may struggle to replace him, giving Indonesia some breathing space to recalibrate its response to extremism, say experts on Islamic militancy in Southeast Asia.
"When he recruited someone, he had a track record [in terrorism]. There are other individuals who have credentials and charisma, but they don't have the same track record as Noordin," says Noor Huda Ismail, a security expert who runs the International Institute for Peacebuilding in Indonesia.
Eyeing resilience of country's militants
But focusing on one man, however dangerous, may overlook the resilience of militant groups in Indonesia, a majority-Muslim democracy with a radical fringe. The death in 2005 of Azahari Hussin, a Malaysian explosives expert seen as Noordin's lieutenant, only proved a temporary setback for terrorism.
"Indonesia may become complacent after his death. But the threat is far from over," says Rohan Gunaratna, head of the International Center for Political Violence and Terrorism Research in Singapore.
A parallel problem is the release of detained militants who have served jail sentences in Indonesia under often lax conditions. At least three of the suspects in the July 17 bombings were former prisoners, according to Mr. Noor, who advises prison officials on how to deal with such detainees.
Skilled at networking
Born in southern Malaysia, Noordin befriended exiled preachers from neighboring Indonesia and veterans of the anti-Soviet jihad in Afghanistan. After the Sept. 11, 2001, attacks on the United States, most opted to regroup in Indonesia. Noordin also fled there, fearing arrest.
Once there, he tapped into the familial and alumni network of Jemaah Islamiyah (JI), an extremist group that advocates an Islamic superstate across much of multifaith Southeast Asia. But Noordin broke away from his patrons when authorities began to turn up the heat on the organization after the 2002 Bali bombings.
In recent years, he led his own splinter cell that recruited young Indonesians willing to die for the cause, even as other radicals began to question the tactic of fighting the "far enemy," as the US is known, in order to topple secular rulers at home.
"He clearly was a proponent of an Al Qaeda ideology, whereas many JI members were beginning to see such a strategy as being counterproductive," says Zachary Abuza, an expert on JI at Simmons College in Boston.
Noordin's cell had sought funding for terror attacks from foreign extremists, though it's unclear if it had direct support from Al Qaeda. Indonesian police said Thursday that they had recovered a laptop and documents from Noordin's safe house that revealed links to Al Qaeda, but gave no further details.
Earlier this month, police arrested a militant website operator in Jakarta suspected of handling money used for the July 17 attacks. The money was couriered by hand from Saudi Arabia, according to Mr. Gunaratna, who says extremists in the Middle East have been funding Noordin's operations.
"They saw him as a natural successor to those who were arrested after Bali I [Bali was attacked again in 2005]. That's why they continued the funding since 2002," he says.
Shortage of middle managers?
In a 2005 video, Noordin reportedly called himself Al Qaeda's representative in Southeast Asia. But that may have been simply a way to assert his leadership over squabbling splinter groups and build a unified network, says Noor. "He wanted to create his own cell," he says.
As Noordin's stature grew, he found it easier to recruit disaffected Muslims who had tired of JI leaders who preach but can't effect change, says Noor, who has interviewed dozens of militants. Many were drawn to Noordin's quiet charisma and ability to elude capture, with police coming close to arresting him on 17 different occasions.
That could prove a tough hole for Indonesian radicals to fill.
"There is a real dearth of 'middle management' for terrorist operations, people who can recruit, train, have technical skills and can fundraise," says Mr. Abuza. "Few people had all those skill sets, but Noordin clearly did."