Table of Contents Relevance to Security  Citizen Status Is  Often Uncertain  Preference Issues  Becoming  Far  More Common   More Countries Allow   Dual Citizenship   More Americans Have   Foreign Backgrounds   More Incentives for   Americans to Exercise   Dual Citizenship  Disqualifying Conditions  Exercise of Foreign  Citizenship  Obtaining Foreign  Citizenship  Open Expressions  of Preference   Examples from Past   Espionage Cases  Citizenship of Close  Family Members Mitigating Conditions  Foreign Passport  Renunciation of  Foreign Citizenship Reference Materials  Glossary of  Citizenship Terms  U.S. Citizenship  Procedures  Citizenship Laws  of Selected Foreign  Countries