Have authorities pursued Jemaah Islamiyah?
Indonesian officials have jailed several members of the group for allegedly planning the October 12, 2002, bombing that killed 202 people at a Bali nightclub. J.I. is also suspected in the August 5, 2003, car bombing of the J.W. Marriott hotel in Jakarta that killed 12. Before the Bali bombing, Indonesian authorities had not aggressively investigated the group, though Singapore, Malaysia, and the Philippines had cracked down on it. After the Bali attack, the United States—which suspects the group of having ties to Osama bin Laden’s al Qaeda network—designated Jemaah Islamiyah a foreign terrorist organization.

Why hadn’t the United States designated Jemaah Islamiyah a foreign terrorist organization before the Bali bombing?
Because of a reluctance to anger Indonesian public sentiment. While Singapore and Malaysia would have supported adding the group to Washington’s list earlier, the United States had been trying to secure Indonesia’s cooperation on the war on terror without alienating its Muslim political parties or undermining its moderate president, Megawati Sukarnoputri. The Bali bombing spurred Indonesia to acknowledge the extent of its terrorism problem, and the U.S. designation followed. Listing J.I. as a foreign terrorist organization restricts the group’s finances and its members’ travel.

Where does Jemaah Islamiyah operate?
Across Southeast Asia, including Indonesia, Malaysia, Singapore, and possibly the Philippines and Thailand. Weak central authority, lax or corrupt law enforcement, and open maritime borders in some of these countries ease J.I.’s ability to operate throughout the region.

When was Jemaah Islamiyah founded?
The name Jemaah Islamiyah dates to the late 1970s, but experts aren’t certain if the name referred to a formal organization or an informal gathering of like-minded Muslim radicals—or a government label for Islamist malcontents. The group has its roots in Darul Islam, a violent radical movement that advocated the establishment of Islamic law in Indonesia, the world’s most populous Muslim country and also home to Christians, Hindus, and adherents of other faiths. Darul Islam sprang up as the country emerged from Dutch colonial rule in the late 1940s, and it continued to resist the postcolonial Indonesian republic, which it saw as too secular.