'Grave injustice'

''Not a single documented act of espionage, sabotage or fifth column activity was committed by an American citizen of Japanese ancestry or by a resident Japanese alien on the West Coast.''

So states the Commission on Wartime Relocation and Internment of Civilians in a report released last week after exhaustive investigation since the commission's establishment by Congress in 1980.

Thus should be dispelled any lingering suspicion that there might have been some justification for holding thousands of Japanese Americans behind barbed wire during World War II.

The report notes that no mass detention was ordered against American citizens of German or Italian descent in any part of the country - though the US was at war with Germany and Italy, too. It concludes a ''grave injustice'' was done to American citizens and resident aliens of Japanese ancestry.

Most Americans have recognized this injustice long since. The commission's work and whatever compensation to the victims that it finally recommends are simply a nation's effort to ameliorate a historical wrong that cannot be undone.