One of the several issues that American voters will hear debated during the long weeks from now to election day is how much aid the United States should give to various political elements in Central America.
How extravagant the debate can become was indicated by a passage on this subject from the keynote address at the Democratic convention delivered by New York Gov. Mario Cuomo. Said Governor Cuomo: ''We give moneys to Latin American governments that murder nuns, and then lie about it.''
Well, Governor Cuomo was taking liberties with the facts. American Roman Catholic nuns were killed in El Salvador, but not by the government. The government, headed by Jose Napoleon Duarte, who is a politician of the center, has tried, convicted, and jailed the men who did the killing.
Did the US government in Washington ''lie about it''? During congressional hearings on aid for the government of El Salvador insensitive remarks were made, implying that the victims of the massacre were possibly working for the communists, hence undeserving of sympathy.
The Republicans have already come back hard on the Democrats. Republicans take the oft-used and familiar line that Democrats are ''soft on communism'' because, in this case, they are reluctant to fund the rebels who are trying to overthrow the communist influenced government in Nicaragua.
All of this is something of a waste of time. A few votes may be influenced by unfair or distorted arguments from both sides. But actual US policy toward El Salvador and Nicaragua has in fact been decided.
No matter which side wins the election in November the Congress is almost certainly going to give continuing support to the recognized, elected, and official government in El Salvador. And the same Congress will almost certainly refuse to go on funding the rebels trying to overthrow the recognized and official government in Nicaragua.
In so doing the Congress will, if unwittingly, be acting according to an old rule of thumb laid down by an astute practitioner of diplomacy, John Foster Dulles.
When he was US Secretary of State during the Eisenhower administration, Mr. Dulles preached and practiced the rule that it is right and proper to give American aid to a government requesting it, provided that government is in effective control of the bulk of the country, is backed by a majority of the population, and can and will be able to fight effectively to defend itself.
The government of El Salvador is in control of most of the territory of El Salvador. The majobRty of the people have voted in two recent elections. Only a small minority abstained as a sign of support for the rebels. Enough of the people are willing to fight for the government to keep its armies in the field and in control of most of the country.
Mr. Dulles would undoubtedly have felt it right and proper to give American military and economic aid to the present government in El Salvador.
But his formula would mean keeping hands off Nicaragua.
The rebels against the government of Nicaragua control virtually no territory inside the country. They stage raids from bases in Honduras and Costa Rica. They have not yet been able to hold an operating base inside the country. There is no evidence that a majority of the people, or even a large minority, support the rebellion.
The funding of the Nicaraguan ''contras'' is strictly an effort to overthrow a recognized government, which is in control of most of its territory and is backed so far as can be proved by a majority of the people who are willing to fight to defend that government.
Congress is following the rules Mr. Dulles laid down. It is doing in respect to these two situations what Mr. Dulles, a devout Republican and enthusiastic cold warrior against communism, would be doing. It is supporting the government in El Salvador but declining to go along further with the attempt to overthrow the government in Nicaragua.
Unless something unforeseeable occurs to upset the equation, this is what the next administration in Washington will be doing, whether the president be Ronald Reagan or Walter Mondale.