Of the 11 million killed in the holocaust, 5 million were not jewish. The Nazi regime exterminated Gypsies, homosexuals, Blacks, the physically and mentally disabled, political opponents, and Slavic peoples, to name a few. Out of all these, Slavic peoples, or Slavs, most closely match the criteria of the question as an ethnic group.
Germany and italy allied, britain, france and american allied. Assaination of the arch duch ferdinand. Sinking of american passenger ship lithunia.....unless i got this confused with ww2
