II IS as essential to go to the war photography exhibit at the Corcoran as it is to stay away.

"The Indelible Image: Photographs of War, 1846 to the Present" is not an easy show to view, with 239 photographs of man's inhumanity to man. It begins with an 1846 daguerreotype of volunteers for the Mexican War, and ends in Beirut and Tripoli, Nicaragua and El Salvador. It continues however much we wish to deny it.

Silence pervades these galleries.

Although the intention of the show is not to shock, it does: with "the earliest known photo of war dead," Indian rebels killed by British troops in a courtyard at Lucknow in 1858; a Civil War soldier, the bottom half of his face missing; limbless children at play; a dead soldier whose flesh has been seared from his face; a Vietcong soldier, "dead approx. 28 hours," covered with maggots and rapidly disintegrating into the jungle floor; a beautiful partisan tortured and hanged by the Germans; a great jumbled heap of eyeglasses in Auschwitz.

This is, intentionally, a universal show, of persons unknown -- no Lincoln, Roosevelt, no Eisenhower -- with the cliche photos carefully omitted. The show's curator, Frances Fralin, says the photographs "were chosen for not who took the picture, or where, but the psychological effect of the picture." About half the photos came from American sources; others came from collectors in England, France, Japan and the Soviet Union.

Within the horror are moments of irony.

Soldiers never change. Civil War soldiers posed for portraits -- "cartes de visite" -- at Point Lookout Mountain. In World War II, GIs dressed in grass skirts for their group picture on an island 60 miles from Guadalcanal. Kamikaze pilots posed for memorial pictures. Bare-chested Navy Air cadets clustered around their training instructor, who looked like the head lifeguard or a football coach. Then there was the human U.S. shield, made up of 30,000 officers and enlisted men standing at attention.

The absurdity, the futility of war. And the picture of asininity: the observers ("high-ranking personnel") who watch "Operation Greenhouse," on board ship at the AEC Pacific Proving Ground, 1951. They wore shorts and goggles for the atomic test, and sat in rows in lawn chairs as if at a picnic.

Identities, nationalities, begin to fuse after a while. Lines of infantry are always inhumanly straight. The camps in the morning have a quiet, ethereal beauty, whether the Indian camp after Wounded Knee, or a cavalry camp in Texas.

A row of graves is just quiet.