Liberals despair that they can do nothing about the Philippines election; President Ferdinand Marcos controls the machinery and will rig it. Conservatives despair that, while hurting us by association, Marcos may be better than the alternatives -- and anyway, there is no way for us to intervene to the extent that would be necessary to influence the election's outcome.

Both are wrong. If the United States, as a matter of policy, wishes to influence the outcome, it can easily do so. Indeed it shall do so, the only question being whether this is by inadvertence or design. After all, as Talleyrand is said to have observed, intervention is a metaphysical concept meaning about the same as nonintervention. Surely that is true for a great power operating in a former colony, with extensive networks of influence -- and even greater psychological networks of assumed power.

William F. Buckley Jr. has raised on this page the possibility that Marcos might even be reelected in a free election -- but few old Filipino hands credit that. If fair observers could supervise every voting booth in the archipelago, Marcos might still win, for the real corruption in the process is less in the box-stuffing that is a historical part of Philippine elections than in the fear of the reprisals that villagers feel are visited upon those who don't do as expected of them. Even before martial law, Marcos had a recalcitrant village burned down, and since then few towns have escaped political punishment of some sort at one time or the other.

Even so, Corazon Aquino can win. She will win in the cities -- the Philippines being the reverse of old Illinois politics in which the Cook County machine was balanced against the downstate Republicans. The provinces are wher Marcos can determine the outcome. Still, the United States has a powerful card to play, as yet unplayed, but long since dealt.

It is the conventional wisdom among rural Filipinos that we have a large influence in their country, far larger than is true. It was always said that no one was ever elected to the presidency of that country in the absence of a perception that the United States backed the winner. Ferdinand Marcos is plainly manipulating that sentiment in the campaign by accusing Aquino of playing with communist support -- not because anyone cares about that as such (for so does Marcos) but because such is taken to mean that America will never support her.

By doing nothing, we are taken to support Marcos. If we do not wish to do so, we must make clear that we support Aquino, through carefully phrased official statements out of our embassy that the wise Philippine electorate will have no trouble deciphering.

After all we have long experience in influencing the outcome of Philippine elections. We openly worked with Ramon Magsaysay for his election in 1953 -- Gen. Edward Lansdale, the "good guy" of "The Ugly American," orchestrated much of it. We need not go back so far. In 1969 Marcos, running for reelection, waged the most expensive and dirtiest election in his country's history. How was it financed? For a year prior to it, he had pressed the United States to permit his government to overprint U.S. government checks to its Filipino employees, to control their flow through specially designated banks. This was at a time of a black market for the peso about a half over the official exchange rate. We knew that if we permitted this to happen, Marcos would use the dollars to gain the difference between black-market and official rates. We balked; it might be a windfall of $50 million to $100 million, obviously depreciating the currency in the process.

Just then, curiously enough, arriving ships of the U.S. Navy were threatened with searches. Now as every Filipino president has known, the United States has a historical policy of not discussing or negotiating nuclear issues (when we can get away with it). That the ships threatened with search were of a "special" character that we did not wish discussed showed the sophistication of Marcos' government. We relented, giving him what he wanted. His subsequent election victory was widely thought to have cost somewhere on the order of $50 million to $100 million.

And in 1972, when he rigged a constitutional convention to subvert the democratic system, he did it in full view of a compliant United States. I was one who knew roughly what was in store, from long conversations with senior American officials in Manila.

If my argument is correct on the facts, there still remains the judgment: do we wish to risk having Corazon Aquino in charge of America's most important military assets abroad? Whatever she is saying now, can she handle the communist insurgency?

I recall her late husband saying, in one of my last conversations with him, that if a not-precisely friendly Fidel Castro couldn't get the Americans out of Guantanamo, why were Americans worried about losing the bases with an avowed friend of the United States such as himself in power? The argument, which showed his keen strategic sense as well as his whimsy, is equally valid for his remarkable widow. She is the last chance for the Philippines, and the last chance for the United States to fulfill in that country President Reagan's message of a democratic crusade that he delivered to the British Parliament in 1982.