Spokesman : Classification of study of troop radicalization unchanged . Report contributor says military classified report after Fort Hood shootings . Comment: U.S. failed to learn from European studies , U.S. representative says .
Spokesman : Classification of study of troop radicalization unchanged . Report contributor says military classified report after Fort Hood shootings . Attention to report might have prevented massacre , co-author says . U.S. failed to learn from European studies , U.S. representative says .