In our monumental capital city, it's sadly appropriate that the newest memorial will not be easily found. Nor will it be the topic of much conversation. In this, the memorial reflects the subject to which it pays belated tribute.

Like countless others adorning the slopes of Arlington National Cemetery, this memorial is small and carved from a granite block. It is a bench, with room for two people to sit, shaded by a white pine and standing a few feet from the cemetery's amphitheater where presidents come to lay wreaths and make speeches about the noble dead not having paid the ultimate sacrifice in vain. Chiseled on the bench are these words:"In sacred memory of those Americans who gave their lives during the Korean War, 1950-1953. 54,246 Died 8,177 Missing in Action 389 Unaccounted for POWs Dedicated on July 27, 1987"

At the dedication ceremony, held under a broiling July sun, there was some lovely singing from a children's choir and a number of nice, obligatory speeches that contained an undercurrent of bitterness. "We came home unannounced, unrecognized and forgotten," said the master of ceremonies, retired Marine colonel Carl L. Sitter, one of several Korean war Medal of Honor winners who attended.

Carmella LaSpada, chairman of the national organization "No Greater Love," formed to remember families and especially children of Americans who died in our wars, echoed the theme of being forgotten. She had checked in an encyclopedia, she told the audience, and found that 26 pages were devoted to World War II, five pages to the Vietnam conflict -- and five paragraphs to the Korean war.

Five paragraphs for a war that in three years claimed nearly as many lives as the 57,685 battle deaths during 9 1/2 years of Vietnam, and with a far higher rate of casualties to number of troops engaged.

LaSpada was largely responsible for the new memorial. The reasons that prompted her devotion were instructive.

Three years ago, during a visit to Arlington, she asked the cemetery superintendent about an interesting-looking pine tree near the Tomb of the Unknown. He told her it was a Korean white pine, planted in 1965 by the then-Korean president in honor of Americans who lost their lives in the Korean war. Where is the memorial to those veterans? she asked. There is none, she was told. LaSpada was further astonished to learn, after checking with Arlington Cemetery officials and the Defense Department, that there was no national memorial for those who served in the Korean war. There had never even been a national remembrance ceremony for them.

Thus, the new Korean war "memorial dedication bench," which redresses an obvious wrong by taking long-overdue public note of a long-forgotten but important war that set a pattern for all American combat since.

I mention all this not to recite ancient history or because that conflict consumed three years of my life and took the lives of friends. I've never joined a veterans' group and have little patience with the professional flag-wavers who often seem to inhabit them.

But there are comparative lessons with the present moment when, once again, Americans are being urged to stop communism -- this time in the jungles of Central America. Divisive and unpopular though Korea was, the debates around that war were open and the decisions openly arrived at -- far preferable to the present situation, where crucial portions of the debate and decision to foster hostilities in Nicaragua took place in secrecy.

I find it interesting that much of the fervent patriotic rhetoric around those decisions now comes from administration partisans (Oliver L. North obviously aside) who never heard a shot fired in anger, never wore their country's uniform, never marched off to the jungles of Southeast Asia and succeeded in avoiding any military service. I find it equally interesting that, unlike Korea, where President Harry S Truman asked and received the support -- and combat troops -- from 17 other nations in the United Nations and also conducted a draft that made Korea a true representation of the nation instead of a mercenary force or a "poor man's war," the Reagan administration has been seeking to do in secret with its covert proxy army what it was unwilling to do in public.

Moral: Get the support of the country before embarking on another military crusade that will result in more monuments with the names of dead Americans chiseled in granite in Washington.