Soon after attacking Afghanistan and toppling the Taleban regime, the United States opened 'the second front' in the global war against terrorism, Southeast Asia. That was February 2002.
The first target was Abu Sayyaf, a tiny Filipino group. But it soon became apparent that the real threat was the al-Qaeda-linked Jemaah Islamiah, (JI) a regional group that fights to unite most of Southeast Asia into a Muslim state.
Back then, JI's operative structure was divided into four districts. These spanned from Malaysia to northern Australia and included southern Thailand, Indonesia, Brunei, Singapore and the southern Philippines. Each consisted of several branches that operated almost autonomously under JI's leader. The first leader was Abdullah Sungkar, who was purportedly succeeded at his death by cleric Abu Bakar Bashir.
Five years on, JI's chief is Abu Dujana, and more than 300 arrests in the region have drastically altered the organisation, which is now deemed less dangerous but still capable of deadly attacks.
'The structure has been weakened; it is a much more fragmented organisation, operating almost exclusively in Indonesia. There is a deepening split between those who follow al-Qaeda's lead and those who do not,' said Sidney Jones, director of International Crisis Group Southeast Asia, and an expert on regional terrorism.
'But the group is still deadly. The security services must remember that JI is a very adaptable organisation,' she said, singling out Malaysian-born Noordin Mohamed Top as the most glaring example of JI's fragmentation.