Alarm bells in America's backyard

Over this past week it has been Washington's turn to worry about events in its own neighborhood.

Is the Soviet Union, operating through its proxies, about to score further serious lodgement of influence in Central America?

Alarm bells had been set off in Washington during the previous week. On Jan. 27 rebel forces in El Salvador scored their biggest military success yet. They attacked the government's main air base at Ilopango just outside the capital, San Salvador. By official admission, they knocked out ''from 30 percent to 50 percent'' of the aircraft on the base.

That meant that in a single raid the rebels had roughly halved the main military weapon -- air power -- which the Reagan administration had put in the hands of El Salvador government forces last year. It raised an immediate question whether the ruling junta in El Salvador had enough effective military strength to be able to use US military aid.

Washington's immediate reaction was to announce an immediate further supply operation to make up for the aircraft losses. But five days later, when Assistant Secretary of State Thomas O. Enders went to Capitol Hill Feb. 1 to vouch that the human-rights situation in El Salvador was improving, his audience of congressmen had in their hands accounts of a particularly unpleasant operation by an El Salvador military unit. The unit was reported to have gone into a civilian quarter of the capital city and raped and murdered harmless civilians.

Mr. Enders had to spend as much time admitting that he found the explanations for the operation unconvincing as he did in trying to persuade his audience that ''the decisive battle for Central America is under way in El Salvador'' and that the US should help save the day there. It may or may not prove such a decisive battle, but the behavior of Washington's proxy troops in El Salvador was not making it easy for the administration.

The three episodes in the latest sequence -- the successful rebel attack on the air base, the civilian killings, and the Washington reaction -- turned the focus on the world scene right around.

Previously, since mid-December, attention had centered on what Moscow's proxy (the Polish Army) was doing in Poland to the Poles. Washington had the luxury seat for pointing the finger at Moscow. The administration even took out world TV time to do so.

But over the past week the Polish story was pushed off center stage. Attention switched to the difficulties Washington continues to encounter in finding proxies in Central America as disciplined, efficient, and effective as Moscow's proxies are for operations in Moscow's neighborhood.

The number killed in the pacification of Poland since Dec. 13 still stands at 17. Poland is a country of 25 million persons.

The population of El Salvador is only about 4 million. But the killing there is averaging well above the same number (17) per day. Both sides seem to kill more or less indiscriminately.

The fighting has been steady and increasingly severe over the past 12 months. The rebels at present appear to be on the offensive. According to US officials, the military supply and resupply of the rebels from Cuba through Nicaragua has continued.

According to both Mr. Enders and Secretary of State Alexander M. Haig Jr., who followed Mr. Enders to Capitol Hill the next day, Nicaragua is now the ''new-found ally'' of Cuba. Cuba, according to both Mr. Enders and Secretary Haig, is ''systematically expanding its capacity to project military power beyond its own shores.''

The official Reagan administration case for more aid to the ruling junta in El Salvador is put in national security terms as follows:

''The decisive battle for Central America is under way in El Salvador. If, after Nicaragua, El Salvador is captured by a violent minority, who in Central America would not live in fear? How long would it be before major strategic US interests -- the canal, sea lanes, oil supplies -- were at risk?

''Unless we act decisively now the future could well bring more Cubas; totalitarian regimes so linked to the Soviet Union that they become factors in the military balance and so incompetent economically that their citizens' only hope becomes that of one day migrating to the US.''

So what we end up with in this early 1982 season is a situation in which both Moscow and Washington are seriously worried about military security in areas each deems to be vital to its strategic interests.

The Kremlin believes that its current troubles in Poland have been deliberately stimulated by Washington in order to weaken Moscow's military position in Eastern Europe.

The White House in Washington seems equally convinced that unrest and rebellion in Central America have been deliberately stirred up by and from Moscow to weaken the US military position in Central America. Neither shows any sign of having the slightest sympathy for the other's predicament.

Both Washington and Moscow are open to the charge of involvement in the other's neighborhood troubles. American union and other funds were sent from the US to the Solidarity union movement in Poland. Guns found their way from communist Vietnam to El Salvador after representatives from El Salvador visited Moscow.

There is no official proof that the US government deliberately supported the Solidarity movement. There is no official proof that Moscow sent funds or guns directly from its own reserves to El Salvador. But each suspects the other.

Destabilization in a rival's neighborhood is a classic power-politics, or ''cold war'' operation. Back during the first ''cold war'' of the post World War II era John Foster Dulles liked to talk about ''giving them some homework.'' He meant stirring up political unrest both inside the Soviet Union itself and in the satellite countries of Eastern Europe.

At present, and in the short term, the Soviets seem to be having the best of this two-way destabilization process. Poland seems to have been more or less restabilized -- for the time being.

A resolution is pending in Congress to forbid any more US military aid to the junta in El Salvador. Mexico and France officially recognize the rebels in El Salvador as ''a representative political force.'' Both are urging a negotiated solution to the civil war in place of the US effort to win it by largely military means.

The week was also marked by the arrival in Washington of Egypt's new President, Hosni Mubarak, who wants President Reagan to apply pressure on Israel toward self-rule for Arabs in the occupied territories.

Mr. Reagan could give Mr. Mubarak what Mr. Mubarak wants only at the price of political troubles at home from Israel's many American friends. The forecast is that Mr. Mubarak, unsatisfied by Mr. Reagan, will gradually move Egypt away from the wholehearted pro-American stance of his predecessor, Mr. Sadat, and nearer to a middle position between Washington and Moscow.