DID YOU SEE that front-page picture of a Guatemalan soldier firing a machine gun out of a helicopter at a village suspected of harboring guerrillas? Nothing could be seen down there except a dog, reported The Post's Christopher Dickey, who was riding along. For many Americans, it must have been a scene reminiscent of the frustrations of the United States' own last war against an elusive guerrilla enemy.

There is one big difference, however. Guatemala's is not an American war. This administration has sent the government a bit of semi-military aid around the edges, but otherwise it has apparently kept hands off, despite its nervousness about the guerrillas. It should keep hands off.

There is a debate over whether and in what ways the United States should support the civilian-military junta in El Salvador but, there is not much to say for supporting the dictatorship of Gen. Romeo Lucas Garcia. Not even those administration officials who lean to accepting him as a useful anti-communist are eager to come forward and make a case for aid.

For good reason. Gen. Garcia, by the word of human rights advocates and American intelligence alike, is the bloodiest leader ruling in the hemisphere. He is ready to advertise his fight against the guerrillas--a fight in which, in one campaign, his chief of staff reports, his forces killed 2,000 people identified as guerrillas. He shields his part in the killing, by the armed forces and by paramilitary death squads associated with them, of literally thousands of civilians. It has been confirmed that these operations are under his direct control.

Noting the slaughter in Guatemala, we asked last year whether it might make sense for the United States to try to acquire a little civilizing influence with the government by resuming the military contacts that Jimmy Carter had cut off. The Reagan administration subsequently gave this policy a certain test, and enough results are in to provide a judgment: it failed. During the period that the administration dangled the prospect of improved ties, Gen. Garcia, evidently misunderstanding the signal, stepped up his policy of indiscriminate civilian killings.

To be sure, guerrilla activity is up, too. And though guerrilla groups go back to the pre-Castro years, some of their current operations are no doubt Cuban-supported. What about that? It's a fair question. But it's a question for Gen. Garcia. He's the one deepening the sea in which the guerrilla fish swim. Perhaps if he comes to realize that his tactics render it out of the question for the United States to support him, he will change his tactics.