Manila, Philippines ? Opening a new front in the war on terrorism, American soldiers are heading into combat on a rugged island in the southern Philippines long notorious for lawlessness and bloodshed.

Some 350 Green Berets are being sent to help poorly trained Filipino troops who have had little success against the Abu Sayyaf guerrilla band on Jolo island, where the Muslim fundamentalist group with ties to al-Qaida is entrenched in jungles that sprawl over jagged mountainsides.

Filipino officers warn the fight on Jolo will be much harder than last year’s operation in which U.S. troops provided training and other noncombat assistance during an offensive that ended a brutal campaign of kidnappings and killings by Abu Sayyaf fighters on nearby Basilan island.

“If the Americans go to Jolo, they should prepare for the worst,” said an intelligence officer, who spoke on condition of anonymity.

The officer, who worked with the Americans last year, said Jolo offered better defensive opportunities for the guerrillas than Basilan because the jungle was not as thick and let them spot troops at a distance.

Supply will be more troublesome because there isn’t a big base to support the U.S. troops as there was on Basilan. The Pentagon says 400 American support troops will work from the port of Zamboanga on Basilan, 70 miles to the northeast.

U.S. soldiers also will come into contact with potentially hostile people more often because Jolo’s airport and the two military camps suitable for U.S. forces sit in crowded neighborhoods on the predominantly Muslim island. Islanders have bitter memories of the U.S. soldiers led by Gen. John Pershing, who crushed a Muslim uprising on Jolo a century ago.

A group of Filipino children follow American soldiers during a town celebration on Basilan island in southern Philippines in this March 2002 file photo. American troops who would take the global war on terror in the nearby island of Jolo against Abu Sayyaf would face more guns and uncertainties than on Basilan.

Jolo is 345 square miles of humid mud flats and forested uplands that look like large clumps of cauliflower from the air. Many white sand beaches and mangrove forests ring the island, a volcanic outcrop on the southwestern end of the Philippines. Most of the more than 600,000 people in Sulu province who live by farming and fishing on the main island of Jolo are among the poorest people in the impoverished country.

Asiri Abubakar, a Muslim who is a professor at the University of the Philippines, said the woeful conditions had bred resentment against the better-off, Christian parts of the country. He said the government needed to provide economic aid and engage in dialogue with the Muslims of Jolo and other nearby islands.

“The problem is from the colonial days and up to this very moment, the island has always been approached with a gun,” Abubakar said.

Jolo has seethed in anarchy and conflict in recent decades, an extension of a long history of bloody feuds among the native Tausug tribesmen as well as with outsiders. Sakur Tan, a former governor, once described Jolo as an infection that makes the whole nation sick.