U.S. Defense Secretary Donald Rumsfeld announced earlier this week that a contingent of U.S. troops will be deployed to the Philippines as part of Washington's post-Sept. 11 anti-terrorism campaign. These soldiers will be operating in hostile territory, and a recent outbreak of violence shows there may be a threat from an unexpected source as well.

Philippine police officers loyal to jailed Muslim rebel leader Nur Misuari have clashed with the country's military forces on the southern island of Jolo, with more than 30 people killed in two days of fighting. The most recent major attack occurred when former members of Misuari's Moro National Liberation Front (MNLF) – who are now part of the police force – fired on an army Jeep Jan. 16.

The fighting comes on the heels of the announcement that more than 650 U.S. troops are heading to train Filipino troops in the volatile southern Philippines region where Muslim rebels with ties to Al Qaeda are highly active. But the Jolo incident has revealed the military's inability to control former rebel elements within the country's security forces. This could prove dangerous for U.S. forces, whose efforts to help Philippine troops fight terror groups may put them in close contact with Muslim extremist elements.

Of the contingent that the United States is sending to the country, 500 will be support and maintenance personnel and 150 will comprise Special Operations forces. They will join about 1,200 Philippine troops for joint counterterrorism exercises. The live-ammunition training will take place in the rebel-infested areas of Basilan Island and Zamboanga.

Washington and the Philippines have never held joint military exercises in these war-torn areas before. But the locations will allow U.S. military personnel to both observe Philippine forces in serious combat situations and train them on how to handle future operations against domestic terrorist elements.

One of the major goals of the U.S.-Philippine military cooperation will be the dismantling of groups such as the Abu Sayyaf – a Muslim rebel organization with strong links to Al Qaeda. More than 5,000 Filipino troops have been deployed to rescue two Americans who were kidnapped by the group but so far have not succeeded.

Philippine President Gloria Arroyo told local radio Jan. 16 that the U.S. soldiers will only be acting as advisers, although Filipino military officials have said that the U.S. trainers would be given live ammunition and are allowed to fire in self-defense, Agence France-Presse reported.

The mere presence of U.S. forces has already angered many in the country, and an attack by hostile separatist groups is a very real possibility. However, another increasing danger is the threat posed by the former rebel elements within the military.

The government integrated rebel members into its military and police forces following the 1996 Peace Accord established between Manila and the MNLF. Over the years both the military and the police have experienced defections as the rebels returned to their former comrades, taking their assigned arms with them.

The recent fighting in Jolo shows that many rebels who have not defected – such as former MNLF members – may not have cut their old ties and may still harbor strong loyalties to factions other than the Philippine government. This has been seen in the past, as former rebels within the security forces have allowed active militant members to pass through security lines or have refused to fight against certain groups.

This may become an even bigger problem for U.S. forces, as the already strong anti-U.S. sentiment in the Philippines could be inflamed by the government's plan to try Misuari for inciting an uprising last year.

Such a catalyst may cause more rebel elements in the military and police to switch allegiances, and their proximity to U.S. personnel can allow them to complicate Washington's efforts in the region or threaten troops themselves.