ICY HELL THE KOREAN WAR: PUSAN TO CHOSIN BY DONALD KNOX Harcourt Brace Jovanovich 697 pages; $24.95

By Michael Walsh

Veterans of American wars have been memorialized in literature, lore and granite. But for the fighters in one bitter conflict, a 1985 commemorative postage stamp has had to suffice. The Korean War is not an event that has lingered in the public memory; its veterans, members of the silent generation, came home with their mouths shut, preferring to keep their angst private. This comprehensive history at last gives voice to their experience and their anguish. On June 25, 1950, Soviet-armed troops from the People's Democratic Republic of Korea charged across the 38th parallel in an attempt to unify the bleak peninsula by force. They quickly swept through the outmanned and outgunned South Korean army. Even the intervention of U.S. soldiers five days later, assisted by a United Nations force, could not stop the advance until it had reached the Pusan perimeter, in the country's extreme southeast corner. But General Douglas MacArthur's bold amphibious counterattack at Inchon, behind the enemy lines, rolled back the North Koreans and resulted in the capture of their capital, Pyongyang. Just as the war appeared to be winding down, Chinese armies poured across the Yalu River, once again reversing the tide. They too were pushed back, but MacArthur was forbidden to invade Mainland China. President Truman, reluctant to widen the conflict, ceremoniously dismissed the angry, defiant general, and two more years dragged by before an inconclusive truce was signed. The net result: both sides were more or less back where they had started, at a cost of 54,246 Americans and more than a million Chinese and Koreans dead. To this day, an uneasy armistice prevails. A formal peace treaty has never been signed. The war left writers as well as politicians strangely silent. Korea inspired no All Quiet on the Western Front, no From Here to Eternity, no Dispatches. Most books on the subject are military histories, bristling with regimental acronyms that only a quartermaster could love. (William B. Hopkins' forthcoming eyewitness account of the Marines at Chosin, One Bugle No Drums, published by Algonquin Books of Chapel Hill, N.C., neatly avoids this trap.) Knox's book does not entirely forswear such an approach. But for the most part, the story is told in the unadorned, often eloquent words of the American dogfaces and grunts who fought there. The painfully complete, troop-movement-by-troop-movement narrative chronicles the war from its beginning to the Marines' heroic breakout at the frozen Chosin Reservoir in 1950. The story unfolds chronologically, with multiple, overlapping narrators. This is war as professional soldiers remember it, calmly and often impersonally; moral nuances are left to the civilians. Marine Private First Class Ernest Gonzalez speaks of the icy hell of Chosin: ''Word was passed to kill all enemy wounded. I found one Chinese curled up, lying facedown. He had a head wound shaped like a perfect pie-cut that exposed his brain. I fired into his midriff. He turned slowly and looked at me as if saying, 'Why must you make me suffer more?' Although it remained a common practice on both sides, I never again killed another wounded Chinese soldier.'' An even greater enemy than the Chinese was the demoralizing cold during the late fall and early winter of 1950, when temperatures dipped down to 30 degrees below zero. Sweaty feet in wet boots froze instantly; food supplies were vaguely flavored lumps of ice. The Marines kept their rifles combat ready by urinating on them, and limbered their machine guns with gasoline. A sergeant in Lieut. Colonel Raymond Davis' battalion ''reached down into the snow and pulled out of a hole a solid chunk of ice that was a Chinese soldier.'' When the officer asked if the man was dead, the sergeant replied, ''No, sir, his eyes are moving.'' As Marines who were there will attest, that was often the only way to determine whether the wounded were alive, and by then it was too late to help. Like the war, Knox's account ends diffidently. Its last entry is a New Year's Eve letter from an Army captain to his mother, composed as he awaited another Chinese midnight attack near Seoul. ''We're kind of stuck out on a limb here,'' he writes. But without too much overt psychic dislocation, most of the men managed to climb down and take their place in society. In a war with no winners, that was the real triumph.