Rep. David E. Bonior (D-Mich.) is doing his lonely best to concentrate congressional and State Department attention on what strikes him as a "glaring conflict" in the Reagan administration's campaign against Soviet-inspired international terrorism.

On the one hand, the Reagan administration cuts off American economic aid to Nicaragua as punishment for helping El Salvadoran rebels. And on the other hand, in not-so-secret armed camps in Florida and California, Nicaraguan and other Latin American exiles are taking training in terrorism and other forms of insurgency with the express purpose of returning home and overthrowing their governments.

That anti-Castro Cubans have been doing this for years (with little effect) has been well-advertised. Given the state of U.S.-Cuban relations, it is easy enough to turn a blind eye. But put yourself in the place of an official of Nicaragua's Sandinista government, with which the United States has diplomatic relations (however delicate at the moment), and the appearance of a gross and damaging double standard is inescapable.

That, at any rate, was how it struck Bonior when, on a recent swing through Central America, he found himself in earnest conversation with Sergio Ramirez, a leading member of Nicaragua's so-called Government of National Reconstruction. As Bonior describes it, "I tried to persuade him how important it was for his government to stop the flow of arms and other support, from Cuba or wherever, through Nicaragua to the rebels in El Salvador."

According to the congressman, Ramirez insisted that his government is not sanctioning this arms traffic and was doing what it could, with limited resources, to stop it.

Now, you don't have to accept that on its face to recognize the force of Ramirez's next point: How can you expect Nicaragua to be able to control everything that goes on within its borders, or across them, he asked Bonior, when the United States does absolutely nothing about former followers of the late Nicaraguan dictator Anastasio Somoza who are openly training on American soil?

Bonior was caught short, for the moment. But on his return to Washington he had no trouble doing his homework. Aides produced for him a copy of the March 15 issue of Parade with a three-page spread of pictures taken by Pulitzer Prize-winning photographer Eddie Adams, which showed Nicaraguan and other Latin exiles in full combat regalia, going through rigorous training exercises only a few miles from Miami.

Adams estimates there are "at least 10 paramilitary organizations composed of Cubans and Nicaraguan exiles operating in Florida. . . . Some of them advertise for recruits over Miami's Spanish-language radio stations and speak freely about their aims. . . . One of the biggest and busiest guerrilla camps in Florida flies a trio of flags at its inner gates -- American, Cuban and Nicaraguan."

Parade is by no means alone in its documentation of this activity. ABC has done a special on "Good Morning American." A recent NBC special on "the amazing story of how anti-communist groups in the United States are outfitting and training private armies" actually ended an evening news report that began with a news dispatch featuring the following quote from Secretary of State Alexander Haig:

"They [the Soviets] maintain 10 training centers in the Soviet Union, in their Eastern European satellites, in Libya, where literally thousands of Third World embryo terrorists are run through a training course to go back to their nations. . . ."

Appearances do matter in the conduct of foreign policy. So the problem is not entirely removed by State Department disclaimers of any hand in what is going on, after all, on private land.

For their part, law enforcement officials insist that the guerrilla trainees in Florida and elsewhere "don't say the same things to us that they do to the press." Authorities insist the case for violations of the Neutrality Act and other U.S. laws would be difficult to prove.

What's missing, however, is any real sign that the U.S. government is even interested in the case. Nicaragua's ambassador to Washington, Rita Delia Casco, says her government has filed formal protests and requests for an explanation for more than two months without even the courtesy of an official reply.

Bonior is not giving up. He's pressing for an investigation by a House subcommittee on inter-American affairs. He makes a good argument:

"If we are to have a litmus test to illustrate our commitment [on international terrorism]," he told the subcommittee, "then I would suggest that the first international terrorists whom the secretary [of state] and appropriate law enforcement officials should bring to justice are those who . . . are operating unlawfully right here in the United States."