The southern Philippines might erupt into ``another Lebanon'' with warring Muslim factions, say close aides of Corazon Aquino, unless the President defuses the situation in coming weeks. ``If you've ever seen a Muslim family feud, this is it,'' says one Aquino official, who finished a tour of troubled Muslim areas on the large southern island of Mindanao Wednesday.
The present ``feud'' has deep roots in ethnic divisions among Muslim Filipinos, but its recent origins can be traced to a move last year by Mrs. Aquino herself.
On Sept. 5, in a dramatic gesture of reconciliation with the country's minority Muslims, Aquino met with Nur Misuari, leader of the Moro National Liberation Front (MNLF) on Jolo, an island largely controlled by his rebels. The gesture anointed Mr. Misuari as the sole Muslim representative. (Muslims are an estimated 4 to 8 percent of the Philippines' 56 million people.)
The meeting, which was arranged by the President's brother-in-law, Agapito (Butz) Aquino, excluded a breakaway faction of the MNLF, known as the Moro Islamic Liberation Front (MILF).
Last week, an outbreak of violence by the MILF against government installations and Misuari's followers gave a strong signal to Aquino that the MILF wanted to be part of government-Misuari negotiations.
Those talks, due to start Feb. 9, entail the granting of some sort of regional autonomy to all or part of Mindanao Island.
Muslim demands for autonomy arose in a militant way during the early 1970s, when the policies of then-President Ferdinand Marcos reopened deep-seated differences between Muslims and the nation's dominant Roman Catholics in Mindanao.
The ensuing four-year civil war cost nearly 100,000 lives and tied up two-thirds of the military in Mindanao, until a settlement was reached in 1976 with the then-unified MNLF. But the pact required the mediation of Muslim member-nations of the Organization of the Islamic Conference. It was known as the Tripoli Agreement, since Libya - the MNLF's financial backer - played broker between Mr. Marcos and Misuari.
Full autonomy promised by the agreement was never granted, however, as Marcos astutely divided Muslim leaders with favors and very limited self-rule.
But the rebel camps of several thousand remained intact.
Hashim Salamat, a former top commander under Misuari, split from the MNLF in 1977 to form the MILF. The new group has grown stronger and bigger than Misuari's MNLF - and the two have often crossed swords.
The MILF is based in western Mindanao. It is more closely tied to traditional Muslim leaders, both in the Philippines and the Middle East, and thus more conservative than Misuari's MNLF, which advocates ``Islamic socialism.'' The MNLF, gets most of its support from the southwest islands of the Sulu Sea.
Christian leaders on Mindanao fault Aquino for not talking to Mr. Salamat's MILF, nor a third small Muslim group. In fact, Aquino at first wanted the Muslims to unify before she opened autonomy talks, but her brother-in-law convinced her to see Misuari first.
Last Saturday, in a damage-control action, Aquino arranged a cease-fire between the military and the MILF by meeting with MILF vice-chairman Haj Murad.
The MILF-MNLF clashes may have erupted for yet another reason. The Islamic Conference plans to meet next Monday in Kuwait, and could attempt to unify the opposing camps for the coming talks, or even favor one over the other. (The flare-up of the Iran-Iraq war could, however, cancel the summit.)
Indonesia, the most populous Muslim nation, has indicated it is ready to use its clout to help the Philippines solve its Muslim problem. That would let the Philippine Army devote full energy to preventing a communist takeover that could threaten Indonesia.
Also complicating the rebel-vs.-rebel situation is the Feb. 2 plebiscite on a new constitution. The draft charter calls for a new Congress to specify the type of autonomy for ``Muslim Mindanao'' and to have such legislation approved by a referendum in affected regions.
Both Misuari and Salamat oppose this measure, since many of their areas that were formerly Muslim have become Christian-dominated in recent decades. Any autonomy referendum might easily be rejected.
Even further complications arise from the fact that the MILF, assisted by one of Aquino's sisters-in-law, Margarita (Ting-ting) Cojuangco, helped Aquino win votes against Marcos in MILF areas in the Feb. 7, 1986, presidential election.
Mrs. Cojuangco is to the MILF what Butz Aquino is to the MNLF: the family connection between Muslims and the President.
The real battle between the two groups may be over who will eventually assume the leadership of a new autonomous government in Mindanao - if the talks succeed with both Muslim leaders present.
The planned Misuari-government talks have aroused resentment among traditional Muslim politicians as well as Mindanao Christians, who distrust Misuari for his ruthless fighting in the early 1970s.
As a concession, Aquino plans to appoint a commission of nonrebel Muslims and Christians to advise her during the talks. And she has downgraded Butz Aquino's role on the government side.