Though not approaching the systematic exterminations by the Nazis, the Japanese record of atrocities -- what victims call ''the Asian Holocaust'' -- is still producing revelations more than 50 years after the end of World War II. The delay illustrates the West's Eurocentric view of wartime suffering as well as striking differences in the willingness of the two former Axis allies to come to terms with their past. It has also thrown a harsh light on cold-war rivalries. As early as 1949, the Soviet Union convicted 12 Japanese for biological war crimes. Although the published transcript contained exhaustive details of Unit 731's crimes, the accounts were largely ignored or dismissed in the West as Communist propaganda. The Allies did, however, prosecute 5,570 Japanese, but none for biological warfare.

In the early 1980's, American and British scholars and journalists rediscovered the germ war issue, adding new details of American involvement in covering up the crimes. The story has since taken on a new momentum and questions of the guilt of Emperor Hirohito persist. Justice Department officials, unfettered by the State Department, are complaining that the Japanese are refusing to provide data on suspected war criminals, who would be barred from entering the country, just as 60,000 Germans and other Europeans are now.

At the same time, a 1997 Japanese lawsuit by Chinese seeks compensation for victims of Japan's germ warfare. Former members of Unit 731 have been confessing crimes. Chinese researchers say they keep uncovering new sites where anthrax, typhoid, plague and other diseases were spread, wiping out perhaps hundreds of thousands of Chinese. Another 10,000 or more Chinese, Russians and perhaps some American prisoners of war as well, researchers say, were killed in ghoulish experiments.

Japanese officials insist they lack proof, although by other accounts they have sealed wartime archives returned to them by the American authorities in the 1950's. With powerful right-wing and militaristic factions long opposed to confessions of wartime guilt, the Japanese publisher of a translation of ''The Rape of Nanking,'' the 1997 best-seller by Iris Chang (Basic Books), postponed its publication.

For decades after the war, veterans of Unit 731 and other biological warfare detachments led Japanese medicine, say scholars like Sheldon H. Harris, emeritus professor of history at California State University at Northridge, and author of ''Factories of Death'' (Routledge, 1994), on the Japanese germ war program.