The vote of an overwhelming majority of the House to withhold 50 percent of military aid to El Salvador was a milestone -- the first time since the rape and murder of three American nuns and a lay missioner in 1980 in El Salvador that the House forcefully demanded reform of the military and serious efforts toward a negotiated settlement.

The Post {"Salvadoran Cease-Fire," editorial, May 25} cautions against a removal of "American restraints" that could "embolden the insurgents."

What American restraints were in place when:

Six leading Jesuit priests and two aides were murdered Nov. 16, 1989, by an army unit that had been trained by U.S. special forces just two days before;

Twenty-eight other Salvadorans were murdered that same week, including labor leaders, university students, university women activists and Indian cooperative farmers; and

Key evidence in the Jesuit murder case "disappeared" and four key witnesses were sent abroad?

Little wonder that the speaker's task force concluded that the investigation of the murders had come to a standstill. In addition, the bipartisan Arms Control and Foreign Policy Caucus of Congress just reported that government and private data show that 14 of El Salvador's 15 top military officers have commanded troops responsible for widespread human rights violations. And 11 of those top 15 officers received extensive training by the U.S. military, both here and in El Salvador.

The only way to signal the armed forces of El Salvador that the United States is determined to see an end to the bloodshed is to threaten their supply line. A majority of the House agreed.

We support the United Nations negotiations, and we support an immediate cease-fire. But we must also recognize that over the past 10 years, U.S. policy has cost taxpayers more than $4 billion and produced no accountability whatsoever in the Salvadoran military.

GEORGE MILLER U.S. Representative (D-Calif.) Washington