Following the September 11 attacks on the United States in 2001 , the Bulgarian government contributed troops to the NATO contingent in Afghanistan which overthrew the Taliban . The Bulgarian Armed Forces continued to provide a contingent of Soldiers ( a reinforced company ) to the International Stability Armed Forces ( ISAF ) under NATO command in Afghanistan through December 2014 . Starting in September 2001 and concluding in November 2005 , the United States Department of Defense , in cooperation with the Department of State and US Ambassador , Jim Pardew , began advising the Bulgarian Ministry of Defense in defense reform in order to assist , train , and prepare the Bulgarian Ministry of Defense and Armed Forces for full membership in NATO . This Defense Cooperation initiative , the Joint Force Modernization Program , had the support of both countries ' governments . In July 2003 , after the United States and its allies invaded Iraq , Bulgaria deployed about four hundred soldiers to the 9,200 member multi-national force under Polish command . The Bulgarian battalion provided logistical support and did guard duty in southern Iraq . The Bulgarian contingent suffered thirteen soldiers and six civilians killed , before it was withdrawn by the Socialist-led coalition government in December 2005 . Hungary and Ukraine pulled out soldiers at the same time . However , in 2006 , the Bulgarian Parliament voted 151 to 15 to send 120 soldiers and 34 support staff to guard the Ashraf refugee camp north of Baghdad
September 11 attacks
September 11 attacks
Bulgaria–United States relations