The arrest in Thailand of an alleged terrorist ringleader and the bombing of a luxury hotel in Indonesia have shed new light on Jemaah Islamiyah, the Southeast Asian affiliate of the al-Qaida terror network.
With the arrest this week of Riduan Isamuddin, better known as Hambali, analysts say Jemaah Islamiyah has suffered a serious blow - but not a fatal one.
Authorities say Mr. Hambali, an Indonesian, not only holds a ranking position in J.I., as the Southeast Asian terrorist organization is known, but is also regional operations chief and money master for al-Qaida.
U.S. authorities say that at a meeting in Malaysia in January 2000, he hosted two of the men who would later be involved in the September 11, 2001 attacks on New York and the Pentagon. Al-Qaida is accused of carrying out those attacks.
He has also been linked by regional governments to a series of attacks in the Philippines and Indonesia, including the bombing of churches across Indonesia on Christmas Eve 2000.
Sidney Jones is an analyst with the European-based think tank, the International Crisis group.
"Hambali's greatest asset was a combination of international contacts and a real strategic sense of where to target, how to target and how to bring the group together so that the attack came off. He was probably responsible for the coordination involved in the Christmas eve bombings of December 2000, for example, where you had 11 cities across six provinces being targeted. It takes a real mastermind to be able to do that," she said.
But Ms. Jones and other analysts say the arrest will not end the group's ability to carry out attacks.
Zachary Abuza, an associate professor of political science at Simmons College in the U.S. city of Boston, says J.I. probably numbers fewer than 1,500 people, but is dangerous beyond its size.
"It's not that large, but it does have a very good and strong cadre of operatives with technical expertise, a lot of skill, a lot of hatred, a lot of charisma, " he said. "The only way we can really defeat this organization is if we can arrest or kill the senior operatives faster than they can be trained."
Despite a series of small attacks, analysts say it took the October 12, 2002 bombing of two nightclubs on Indonesia's island of Bali, and the bombing this month of the J.W. Marriott Hotel in Jakarta, to remove any lingering doubts that Jemaah Islamiyah had taken root in Indonesia.
Two hundred two people were killed in Bali, while 12 have died and scores were injured in the hotel bombing. Indonesia's defense minister says J.I. is behind both bombings, but senior police officials say it is too soon to tell.
Indonesia's top security minister says such debate is beside the point, and Indonesians must accept the reality of terrorists in their midst.
Susilo Bambang Yudhoyono says the fact is, another terrorist attack has taken place, and it took place in the capital. He says that is the proof that terrorists are active in Indonesia.
Since the Bali attack, authorities have taken a closer look at one source of J.I.'s foot soldiers - an Islamic boarding school founded by the group's alleged spiritual leader, Islamic cleric Abu Bakar Bashir.
Mr. Bashir, 65, is now on trial in Jakarta for his alleged role in the December 2000 church bombings and other terrorist plots.
His school, al-Mukhmin, is part of the conservative "Ngruki" network of Muslim schools. Ngruki is not a terrorist organization, but officials say Asmar Latinsani, the suspected suicide bomber in the Marriott attack, graduated from Mr. Bashir's school. So did two other J.I. suspects who helped police identify Mr. Asmar's remains.
"Even though there are thousands of students who go through Ngruki and don't end up as terrorists, I think it remains the case that it's not a coincidence that we have so many people linked to Ngruki who have taken part in various bombings," said Sidney Jones, "and that we have as head of the J.I. network the man who was most associated in the public's mind with Ngruki."
Professor Abuza of Simmons College agrees, and says other groups of Indonesians may also fall under the influence of Muslim extremists.
"One of the things that really bothers me right now is that you have a fairly literate and computer-savvy group of college students right now in Indonesia with very little hope for employment," he said. "And so they sit around all day and they hack and they surf the Net and they learn their Islam online. They don't really understand Islam very much. They're simply getting some very simplistic and raw understanding."
Indonesian officials have said they want to question Mr. Hambali, who is reportedly in U.S. custody.
No matter where he is questioned, Southeast Asian governments hope his arrest will reveal more about the extent to which religious extremism and its violent corollary, terrorism, have permeated the region.