Book excerpt: The first intensive study of FDR's foreign nationalities policy Lorraine M. Lees explores the persistent tension between ethnicity and national security by focusing on the Yugoslav-American community during World War II. Identified by the Roosevelt administration as the most representative example of the ethnic conflict they sought to address, the Yugoslav-American community suffered from a severe political split, as right-wing monarchists loyal to Mihajlovi ́c and the Chetniks battled left-wing supporters of Tito's partisans. Lees examines the views of two groups of administration policy makers: one that perceived America's European ethnic groups as rife with divided loyalties, and hence a danger to national security; and a second that viewed such communities as valuable sources for political intelligence that would help the war effort in Europe. Yugoslav-Americansand National Security during World War II is significant not only to understanding the Roosevelt administration's equation of ethnicity with disloyalty, but also for its insights into similar attitudes that have arisen throughout periods of crisis in American history as well as today.