A once nonpolitical Philippine military shows some dissent

''Let's face it,'' said an officer, ''without the military at the moment - with demonstrations in the street and the economy tottering - Marcos would be helpless.''

This is what worries many civilians. As President Ferdinand Marcos's power declines, the Armed Forces of the Philippines (AFP) seem to be inching toward center stage. Many opponents of Mr. Marcos and even some of his supporters fear that the military, led by Gen. Fabian Ver, the AFP chief of staff and the President's virtual alter ego, will intervene, either to reimpose some form of martial law or to appoint a successor of their choice when Marcos leaves the scene.

To a certain extent the President seems to be fostering this fear in an effort to cling to power. But there are signs the ferment affecting the rest of Filipino society is slowly seeping into the military.

Some officers say the military's unquestioning loyalty to the President has been shaken by the assassination of opposition leader Benigno S. Aquino Jr. last August. They have begun to express their concern about high-level military corruption and to suggest that General Ver's authority might not outlive the President. And some of them have begun to talk to political dissidents in the business community.

General Ver and his top commanders have been very visible recently. In November they made two well-publicized and unprecedented appearances at the highest councils of state.

On Nov. 4, General Ver and his colleagues showed up, on the President's invitation, at a meeting of the Cabinet and executive committee. (Until late November the executive committee was charged with ensuring a smooth succession, should anything happen to the President.) The following week Ver and senior commanders appeared at a caucus of leaders of the President's political party, the Movement for a New Society, known by its Pilipino initials KBL.

On both occasions General Ver's tone was ostensibly one of reassurance and devotion to the Constitution. But both appearances provoked angry and fearful comments from government supporters and opponents alike.

''I don't like it,'' said Arturo Tolentino, a ranking member of the KBL. ''It creates a bad impression.''

Mr. Tolentino made it clear that he had not been impressed by ''Mr. Ver's'' presence at the KBL caucus. Tolentino says he and other KBL leaders pointed out that the presence of the generals at the caucus was unconstitutional, and the soldiers left.

Other observers found the two incidents frankly sinister.

''I think the meaning is clear,'' said Jaime Ongpin, president of the giant Benguet Mining Corporation and brother of a government minister. ''The President was showing that the military was behind him - and that it was either him or the military.''

The military presence at both meetings follows months of rumors of Army contingency plans for the arrest - and perhaps execution - of thousands of government supporters. The opposition says the plan is called ''Operation Mad Dog'' and was drawn up by General Ver.

No proof of the plan's existence has been offered, but many of the President's middle-class opponents are convinced it exists.

''I think it is realistic,'' a senior executive said, ''and from the military's point of view, quite logical. Our military have a lot of contact with the Indonesian Army, and remember how they solved their dissident problem there.'' He was referring to the massacres that followed an abortive leftist coup in Indonesia in 1965, when hundreds of thousands of people were killed.

Marcos himself seems to have been the source of one of the most detailed versions of this rumor.

Last September, while the first phase of antigovernment demonstrations was in full swing, the President met a group of businessmen for a lengthy and at times acrimonious discussion of the situation.

According to one of the participants, Ricardo Romulo, a prominent lawyer and the son of the Philippine foreign minister, Marcos warned them that his military had a ''battle plan.'' It called for the arrest of between 2,000 and 10,000 opponents. ''That would put an end to all this trouble,'' Mr. Romulo said Marcos told the businessmen.

''We protested that this would exacerbate things,'' Mr. Romulo said. ''The President replied that he had urged the military to scale down the number, just start with the dregs of society, perhaps 2,000. We didn't dare ask who the dregs were, in case they included us.''

''But the military is laughing at me,'' Romulo says the President continued. ''They say even that (arresting the dregs of society) would mean at least 5,000 people.''

In addition to conjuring up the rather scary picture of a military command slipping out of control, President Marcos has made blunt threats of military intervention.

Speaking on television Nov. 26, Marcos reminded ''mischievous elements'' in the opposition of the existence of the Citizens' Army Reserve, a unit approximately 1.4 million-strong which theoretically can be mobilized in 72 hours - and which is commanded by a brother-in-law of First Lady Imelda Marcos.

Mention of the reserve not only underlines again the enormous power that Mrs. Marcos has at her disposal, but may also remind the regular armed forces that the President has other means at his disposal should they prove recalcitrant.

Such threats not only reinforce many Marcos opponents' fears of a military coup or the reimposition of martial law. They also fuel the suspicion that some members of the government, military and civilian, are no longer thinking rationally.

But more optimistic dissidents, who still feel reason prevails, say they do not expect military intervention. They point out that the priority of the moment is the restoration of the economy: Military intervention would make things worse , not better.

They also feel that times have changed since 1972, when President Marcos declared martial law. Then, the decision seemed to have the tacit compliance of the majority of the population. Now the President's credibility has gone, and the once-silent majority is out in the streets.

Potentially the most significant change, however, is the one taking place among some military officers.

Like many civilians, some officers suspect the government and their commanders were involved in the killing of opposition leader Aquino.

''. . . Which shows you there are some pretty lousy people running our military,'' said a staff officer. The murder seems to have helped focus some of the long-festering grievances among the officer class.

''If emergency powers were declared,'' said a senior staff officer as we sat in a large military base, ''a lot of these people would follow orders.'' He gestured to the clerks and privates bustling across the parade ground in front of us. ''But more senior guys like us would not.''

Such opinions openly expressed to a foreigner are new, but it is impossible to judge the extent to which they are shared by the officer corps as a whole.

A senior general, now retired but in close contact with serving officers, feels they are widespread.

''It would be a close decision,'' the general said, ''but a majority of the officer corps might just go against special powers. That is, they would be at best unenthusiastic in carrying out orders.''

Both the dissident officers and the retired general share the same reasoning: There is large-scale corruption at the top of the AFP, but it is limited to a relatively few officers. These officers enjoy immunity because of their allegiance to General Ver and President Marcos. They impose authority because of the hitherto unquestioned authority of the President, and tight internal security in the AFP. This pyramid of power may begin to crumble when the President goes.

''Not too many of the younger officers have been contaminated by these (corrupt) practices,'' said the general. ''Many more have failed to get promotion because of these overstaying commanders blocking the ladder.''

Some of the officers have begun to rough out the changes they would like to see.

They want Ver to be replaced by Lt. Gen. Fidel Ramos, assistant chief of staff. ''He's comparatively clean,'' a staff officer said, ''he's not stupid (many officers feel General Ver is), and he has the support of the business community.''

Some, probably many, of the present military commanders will have to go. One officer called them the ''military cronies,'' drawing a parallel with businessmen who are close friends of Marcos and who have done well from the regime.

And some AFP units alleged to be more deeply affected by corruption - for example, the Philippine Constabulary - will have to undergo a more extensive housecleaning.

Some of these plans seem to have been influenced by contacts with the business community. Enrique Zobel, one of the country's most successful and biggest businessmen (and also a colonel in the air force reserve) is thought to be one business leader who has had contacts with soldiers. Army officers say there have been others, but they will not name their interlocutors. Another newfound dissident, Defense Minister Juan Ponce Enrile, reduced to political impotence by General Ver earlier this year, may also be acting as an intermediary between business and military.

But like the businessmen, the soldiers seem to be unsure how to implement their ideas. They appear to have little or no organization, to be half actors, half spectators in the drama taking place. Their lack of plan may eventually allow General Ver to consolidate, at least temporarily, his position. But any unity Ver is able to achieve will be only cosmetic.