A 23-year coverup has ended at the State Department. The warlike mural in the building's 21st Street lobby - which shows scores of U.S. soldiers fighting for our freedoms (and wiping out our enemies) - is on view again.

When Kindred McLeary painted it in 1941, his crowded compositin of warplanes, screaming eagles, corpses, fires and big guns, was thought "spiritually in accord with the ideals to which his country is reawakening." The Foggy Bottom building housed the War Department until 1947, when that department left for the just-completed Pentagon, and the diplomats moved in. The mural, with its implied threat and its heavy-handed celebration of America the mighty, made many of them blanch.

In 1954, the 50-feet-long painting was decreed "inappropriate" and covered with a drape.

"We thought of it as a sort of secret weapon," says one Foreign Service officer. "If diplomacy failed, we could always pull the curtain."

It wouldn't have been easy. The curtain wouldn't pull. It was hled in place by two-by-fours bolted to the painted wall. Washington restorer H. Stewart Treviranus is now patching the bolt holes, repairing the cracked plaster, and making the old mural presentable again.

"Defense of Human Freedoms" is the name McLeary gave it. Once seen as a battle cry, then as an embarrassment, it now seems an antique.

It has a cast of hundreds. While War rages around them, unsmiling civilians - newboys wearing knickers, old men hanging out, preachers, politicians - pursue democratic freedoms as if it were their duty. None of them appear to be having fun.