The conflict in Kosovo represents a significant watershed in post-Cold War international security. Interpreting its political and operational significance should reveal important clues for understanding international security in the new millennium. This text analyses the international response to the crisis in Kosovo and its broader implications, by examining its diplomatic, military and humanitarian features. Despite the widely held perception that the conflict in Kosovo has implications for international security, unravelling them can be challenging, as it remains an event replete with paradoxes. There are many such paradoxes. The North Atlantic Treaty Organisation (NATO) entered into the conflict ostensibly to head off a humanitarian catastrophe, only to accelerate the catastrophe by engaging in a bombing campaign; the political aims of all the major players contradicted the military means chosen by them in the conflict. The Russian role in the diplomatic efforts demonstrated that NATO did not want Russia to be involved but in the end needed its involvement. Russia opposed the bombing campaign but ultimately did not have enough power or influence to rise above a role as NATO's messenger; the doctrinal hurdles to achieving ‘immaculate coercion’ by use of air power alone seemed to tumble in the face of apparent success; it is ultimately unclear how or why NATO succeeded.