IF KOREA is America's forgotten war, the Army's role in the retreat from the Chosin Reservoir after the Chinese intervention in the winter of 1950 is virtually unknown. Mention "Chosin Reservoir" to even those those knowledgeable about Korea and the Marine Corps immediately comes to mind. Few know that along with the 1st Marine Division were some 3,000 soldiers of the Army's 31st Infantry Regimental Combat Team -- also known as Task Force Faith after its commander, Lt. Col. Don C. Faith, who was awarded a posthumous Medal of Honor for his actions during the withdrawal.

East of Chosin is their story, and it is not a pretty one. "The fate that overtook Task Force Faith," writes historian Roy E. Appleman, who also wrote the first volume of the Army's official Korean war history, South to the Naktong, North to the Yalu, "was one of the worst disasters for American soldiers in the Korean war."

After four days and five nights' combat against the Chinese Army's 80th Infantry Division in late November and early December 1950, only 385 soldiers of the original 3,000-man force survived. Fighting in temperatures that at times dropped to 35 degrees below zero, over 1,000 were killed, captured, or missing in action and some 1,500 had been wounded and evacuated from the battlefield.

Well written and meticulously researched (including interviews with many survivors of the action) East of Chosin is military history at its best. Highly recommended for those who would know about America's forgotten war.

AND THE Korean war is not all that has been forgotten. Puzzlement is probably the most common reaction among tourists who come upon the imposing equestrian statue over the grave of Field-Marshal Sir John Dill in Arlington National Cemetery. Few would know that Dill was a key figure in the Anglo-American high command during World War II. As chief of the British Joint Staff Mission to the United States and senior British representative on the Combined Chiefs of Staff from December 1941 until his death in November 1944, he was in a key player in the Allied war effort.

What makes his present obscurity so undeserved is that in life it was America, not Great Britain, that fully recognized his enormous talents. Upon his death "official Britain was parsimonious in word and deed," but in America there were "unanimous expressions of profound and genuine regret," points out author Alex Danchev, a serving officer in the British Army and former lecturer at the Royal Military Academy at Sandhurst.

His Very Special Relationship explores the reasons for Dill's success in Washington. Of special interest -- now that Congress has recently sought to fix by legislative fiat how the Joint Chiefs of Staff ought to work -- is Danchev's portrait of how such general staffs work in reality. It was not organizational charts but the interactions of personalities -- especially the interactions among Dill, American Army Chief of Staff George Marshall and British Army Chief of Staff General Sir Alan Brooke -- that enabled the Joint Chiefs of Staff's predecessor, the Combined Chiefs of Staff, to become the architects of victory in World War II.

IN East of Chosin, historian Appleman notes that because many of the eyewitnesses were now deceased "a substantial segment of our history was on the verge of being lost forever." If that is so of the Korean War, it is even more true of earlier wars.

One way military historians have sought to preserve such first-hand accounts is through an extensive oral history program. A Journey Among the Good and Great is an example of such works. Written by retired Navy captain Andy Kerr, it is based largely on the transcripts of seven oral history interviews Kerr provided to historians at the U.S. Naval Institute in Annapolis.

Commissioned from the Naval Academy in 1944, Kerr survived a Japanese torpedo attack on the cruiser Honolulu at Leyte Gulf, and later served on the submarines Sea Fox and Clamagore. Removed from line duty for physical reasons, most of Kerr's subsequent career was spent as a naval lawyer, including service as special counsel to secretaries of the navy John Connally, Fred Korth and Paul Ignatius.

As with Danchev's account of how high-level staffs worked in World War II, Kerr illustrates the political and military machinations common at the highest levels of the Navy. His insider accounts of such controversies as the squabble over the TFX fighter (that's the aircraft that Secretary of Defense Robert McNamara wanted to procure for both the Navy and the Air Force), the relief from command of Lt. Cmdr. M.A. Arnheiter (and the subsequent attention from the media) and the Tonkin Gulf incident are particularly interesting.

WHILE ORAL history is a relatively recent phenomenon, a more traditional method of retrieving eyewitness accounts of war is through letters written by soldiers on the battlefield. Collections of letters ranging from the American Civil War through the war in Vietnam have been published, and four years ago Annette Tapert, who put together the present collection of letters from World War II, also published Despatches from the Heart, a collection of letters from World War I.

During World War II, from 1942 to September 1944, more than 789.5 million V-Mail letters were sent to and received from American soldiers abroad. While many have long since been lost or destroyed, a significant number still remain. Thanks to the collection at the Army's Military History Institute and elsewhere and to the response to appeals from the public at large, Tapert was able to put together more than 100 letters, many accompanied by photographs, arranged chronologically from Pearl Harbor through the end of the war.

Celebrity letters -- from John F. Kennedy, George Patton and the like -- are included, but most are from ordinary soldiers, sailors, airmen and marines. They tell what it was like in North Africa, in Italy, on the beach at Normandy or Peleliu or Leyte. Written in plain language and never intended for publication, these letters are as close to the "truth" about war as those who have never been under enemy fire can possibly get. :: Harry G. Summers Jr., a contributing editor to U.S. News & World Report and a syndicated columnist for The Los Angeles Times, is the author of "On Strategy" and the "Vietnam War Almanac."