Riduan Isamuddin also transliterated as Riduan Isamudin, Riduan Isomuddin, and Riduan Isomudin, better known by the nom de guerre Hambali, born as Encep Nurjaman (April 4, 1964) is the former military leader of the Indonesian terrorist organization Jemaah Islamiyah (JI), which is linked with al-Qaeda. He is now in American custody in the United States's Guantanamo Bay detainment camps, in Cuba. He is currently awaiting trial in a military commission.Hambali was often described as "the Osama bin Laden of Southeast Asia". Some media reports describe him as bin Laden's lieutenant for Southeast Asian operations. Other reports describe him as an independent peer. He was highly trusted by al-Qaeda and was the main link between the two organisations. Hambali was a close friend of Khalid Sheikh Mohammed, who planned Operation Bojinka and the September 11 Terrorist Attacks. Hambali envisioned creating a Muslim state, in the form of an Islamic superpower (a theocracy) across Southeast Asia, with himself as its leader (Caliph). His ambition was to rule Indonesia, Malaysia, Singapore, Brunei and parts of the Philippines, Myanmar, and Thailand.He received increasing attention in the aftermath of the 2002 Bali nightclub bombing, in which 202 people died.

He was eventually apprehended in a joint operation by the CIA and Thai police in 2003. He is currently imprisoned in Guantanamo Bay detention camp in Cuba, after three years of CIA custody in a secret location.

Jemaah Islamiyah (Arabic: الجماعة الإسلامية, al-Jamāʿah al-Islāmiyyah, meaning "Islamic Congregation", frequently abbreviated JI) is a Southeast Asian militant extremist Islamist terrorist group based in Indonesia, which is dedicated to the establishment of an Islamic state in Southeast Asia. On 25 October 2002, immediately following the JI-perpetrated Bali bombing, JI was added to the UN Security Council Resolution 1267 as a terrorist group linked to Al-Qaeda or the Taliban.JI is a transnational organization with cells in Indonesia, Singapore, Malaysia and the Philippines. In addition to al-Qaeda, the group is also thought to have alleged links to the Moro Islamic Liberation Front and Jamaah Ansharut Tauhid, a splinter cell of the JI which was formed by Abu Bakar Baasyir on 27 July 2008. The group has been designated as a terrorist group by the United Nations, Australia, Canada, China, Japan, the United Kingdom and the United States. It remained very active in Indonesia where it publicly maintained a website as of January 2013.On 16 November 2021, Indonesian National Police launched a crackdown operation, which revealed that the group operated in disguise as a political party, Indonesian People's Da'wah Party. The revelation shocking many due to this is for the first time in Indonesia a terrorist organization took disguise as a political party and attempted to intervene and participate in Indonesian political system.