Despite the new accord, government negotiator Marvic Leonen called for "guarded optimism" during last week's negotiations in Malaysia's main city, Kuala Lumpur, saying both sides still face the enormous task of threshing out details.
And the challenges are many.
In 2008, the planned signing of a similar preliminary pact was scuttled when opponents went to the Supreme Court, which declared the agreement unconstitutional. Fighting erupted when three rebel commanders attacked Christian communities, and an ensuing military offensive killed more than 100 people and displaced about 750,000 villagers before a cease-fire ended the violence.
One of the hard-line rebel commanders, Ameril Umbra Kato, broke off from the Moro rebels last year and formed a new group opposed to the talks. Kato's forces launched attacks on several army camps and outposts in August, prompting another army offensive that killed more than 50 fighters of the 200-strong rebel faction.
The Moro Islamic Liberation Front itself broke away in the 1980s from the Moro National Liberation Front, which signed a 1996 autonomy deal with the government. That peace accord did not lead to the group's disarmament and many of the rebels have simply laid low in the south, still demanding that the government fulfill its commitments, including jobs, security and economic development.
Some former guerrillas also formed a small but brutal al-Qaida-linked group called the Abu Sayyaf, which became notorious for bombings, ransom kidnappings and beheadings until U.S.-backed Philippine military offensives routed many of its militants. They are mostly based in the southern provinces of Sulu and Basilan, where about 400 gunmen remain.
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