THE United States is heading into a couple of important tests of its fidelity. The question is whether Washington will stand by its friends in Afghanistan and Nicaragua - both groups battling Marxist regimes - or whether political considerations will cause their abandonment.
In the past, circumstances have conspired against some freedom-inspired fighters who threw in their lot with the US, but who were jettisoned in time of crisis.
After the ill-conceived Bay of Pigs venture, Cubans who had fancifully sought to free Cuba from Fidel Castro were left to fend for themselves on a beach-head overrun by Dr. Castro's superior forces. And in Vietnam, when an exhausted America withdrew, thousands of Vietnamese who had enlisted in the fight against the communist North were left to the far-from-tender hands of the Marxist victors. Boatloads of Vietnamese refugees still flee from Hanoi's rule over their country.
Now it is the turn of the Afghans, who have resisted occupation of their country by a Soviet army, and of the Nicaraguans who have taken up arms to break the grip on their country of the Marxist-enamored Sandinistas.
In Afghanistan, the beleaguered Soviets are about at the end of their military tether, having been held to a standoff by the anticommunist guerrillas. A few hitches are stalling their promised military withdrawal. One is President Reagan's insistence that they stop military aid to the Afghan forces they will leave in place before the US stops its aid to the freedom fighters. This should be a staunch US position. To do otherwise would be unconscionable.
What the Soviets are trying to do is shape the future of Afghanistan - to win politically what they have failed to win militarily. Of concern to Moscow is any perception of ``weakness'' in Afghanistan. That, the Soviet leadership fears, might encourage ethnic separatists in the Soviet Union, or hearten Eastern European countries, to follow courses more independent of Moscow.
But the US has no obligation to bail out the USSR in Afghanistan. The American obligation is to the guerrillas who have fought so bravely, and to the 5 million Afghan refugees who have been displaced from their country. They should not be left to the retribution of a Soviet rump regime in Kabul, with a continuing supply of military aid from Moscow.
The Afghan guerrillas are a tough, cantankerous and not-necessarily-democratic medley. But they deserve better than to be left without bullets to face the guns of Afghanistan's Soviet puppets.
Unless the US role in Nicaragua is to end in infamy, the same must be said of the Nicaraguan contras. Just days before the rescheduled resumption of cease-fire talks with the ruling Sandinistas, they have been facing a new Sandinista military offensive. They have been facing it without the support of the on-again, off-again US Congress, which has alternately voted aid and then cut it off, depending on its whim. Currently the aid is turned off, and despite Ronald Reagan's urging, Democratic leaders are not inclined to vote on a new package.
Like the Afghan freedom fighters, the contras are quarrelsome at times among themselves, and have been guilty of excesses and human rights abuses - just like the Sandinistas. The Sandinistas have resurfaced their ``turbas'' - gangs of rock-throwing thugs used to break up opposition political meetings. The ``turbas'' were curbed in 1984, but have apparently been given the Sandinista green light to operate again.
Though the contras may not be ideal democrats, they too deserve some consistency of US support.
John Hughes will resume his column April 1.