One trouble with apologists for the Nicaraguan rebels is that they can't keep their minds on the subject.

The subject, as President Reagan defined it in his speech Sunday night, is whether we serve democracy and our own well-being by financing the contras. In my judgment, we do neither. The contras are not democrats -- either by conviction or by popular support -- and have fought a foul campaign that harms our real interests in the hemisphere.

Jeane Kirkpatrick (op-ed, March 17), by way of rebuttal, assures me that the contras are "working hard to avoid harming civilians." She then commences a discourse on the "shocking denial of rights" in Nicaragua.

It is a clumsy sleight of hand. After all, I am not proposing to finance the Sandinistas, and indeed I denounce them. Jeae Kirkpatrick does propose to finance the contras, but the most she will vouchsafe their conduct -- and even this without evidence -- is that they are "working hard" to improve it.

Let us be clear. The contras are not "harming civilians" in some careless way that hard work might prevent. As Americas Watch and Amnesty International have taken pains to document, they are raping, mutilating and puttting civilians to death.

The means of our proxies should matter to us. So should their ends. In this context you have to marvel at Kirkpatrick's claim that the contra leadership "is drawn almost wholly from men who actively opposed Somoza . . . and sought to bring democracy to Nicaragua."

Col. Enrique Bermudez, the founder and supreme military commander of the major contra force, was one of Somoza's most trusted and senior henchmen. Twelve of Bermudez's 13- strong high command were likewise officers of Somoza's National Guard. Many of them were personally responsible for the brutal repression of the old regime. And it is these men, not the campesinos and not Arturo Cruz, who would be the chief beneficiaries of military aid.

Kirkpatrick seeks comfort in the view of Nicaragua's neighbors. A poll, she says, shows that despite all appearances, Central Americans support military aid to the contras. In fact, the most recent data, including those from the very poll she cites (by the Consultoria Interdisciplinaria in Desarollo), show a rather different result: Central Americans greatly dislike the Sandinistas, think little better of the contras and are deeply divided on the question of military aid.

Kirkpatrick's enthusiasm for an unpromising line of exegesis may lie in the alternative: the united and vocal opposition of the elected governments of Latin America.

Eight foreign ministers came to Washington last month, from among the very nations most imperiled on the president's television map. Mexico. Colombia. Venezuela. Panama. Argentina. Brazil. Peru. Uruguay. They begged George Shultz to settle the contra war.

As Charles Krauthammer points out (Topic A, March 16), this is the last thing the president wants. In our stylized national debate, he pretends to seek military aid as a lever to move the Sandinistas to the table. The converse is closer to the truth: Congress, rightly skeptical, withholds the aid to move the president to the table.

We opponents of this conflict, Krauthamind of charade: seeking regional security and not the military destruction of the Sandinistas, we only "pretend (to) care about democracy" in Nicaragua. "Can anyone," he asks, "present a remotely plausible scenario in which the Sandinistas, unforced, either relinquish power or permit a free competition for power?"

Plainly not. But that's the wrong question. I would ask: where is the real force for democracy? Krauthammer believes it is the contras. I do not.

The contras, it is said, are the only barrier to consolidation of the Sandinista regime. Really? If we had set about plotting to keep Daniel Ortega in Managua, could we have done any better than a CIA-financed rebellion with scarce support from the populace and no prospect of success?

The contras confer an ersatz legitimacy, by way of nationalism, on a repugnant regime. They offer the Sandinistas a rationale for repression while doing little concretely to prevent it. If the Sandinistas have not yet consolidated their power, and they have not, there is another reason.

Democracy, in Nicaragua as elsewhere, is about the loyalty of its people. Nicaraguans resent the Sandinistas. We must allow them to concentrate on that resentment -- and not on their hatred for the old regime.

Nicaraguans after the contras would be something like Poland with no Soviet border: a sullen people, a crumbling economy, the lure of freedom in near neighbors, and an inspiring example in the church -- but not the slightest prospect, if America does what it must, that the Soviets will render "fraternal socialist assistance." Not for long would Nicaraguans consent to be the laggards of the hemisphere.