Jim Fish in his article on Yugoslavia {Oct. 20} points out that 500,000 Serbs in Croatia have "long and bitter memories of the slaughter of uncounted thousands in World War II concentration camps run by in the fascist puppet 'Independent Capital State of Croatia' " and that these memories, suppressed for 40 years by Tito, a Croat, are now firing rival nationalistic passions.

Have the Serbs in Croatia reason to be concerned and ask for autonomy? Or is it only a plot hatched by Serbian Communists as claimed, according to Mr. Fish, by Croatian leaders?

At the inaugural meeting of his party last February, the present president of Croatia, Franjo Tudjman, declared that the Independent State of Croatia had not been just "an accidental quisling creation" but that "it also represented historic aspirations of the Croatian people."

The Independent State of Croatia was formed in 1941 by Ante Pavelic, who annexed to it Bosnia, Herzegovina and parts of Serbia, thereby creating a state that included more than 2 million Serbs. Mr. Pavelic's aim was to make this new state ethnically pure; consequently more than 700,000 Serbs, 30,000 Jews and an indeterminate number of Gypsies were exterminated while 200,000 Serbian Orthodox Christians were forcibly converted to Catholicism.

After the war, Germany admitted its crimes against the Jews. Croatia has never admitted its crimes against the Jews, the Gypsies and the Serbs. Mr. Tudjman won the elections after an overtly anti-Serb and anti-Jewish campaign. The more conciliatory statements made recently by Mr. Tudjman will not reassure the Serbs until he withdraws his support of the Croat wartime fascist state, particularly because he has reintroduced into his administration the terminology once used by Mr. Pavelic. Nor is the fact that Mr. Tudjman was freely elected reassuring in itself.

One should remember that Adolf Hitler also came to power as a result of free elections. Is it surprising then that, like the Jews, the Serbs are now saying "never again"?