Walker was subsequently appointed to head the Kosovo Verification Mission , leading some 1400 international and 1500 local staff between October 1998 and June 1999 along with British Major General John Drewienkiewicz , Walker 's military adviser . This was a peacekeeping mission mounted by the Organization for Security and Cooperation in Europe in an unsuccessful attempt to halt the ongoing violence in Kosovo . In 1999 , following the Račak massacre , Walker was putting pressure on forensic experts headed by Finnish pathologist Helena Ranta to name the perpetrators of the massacre ( Serbian security forces ) , thus way wanting justification in the international community for the later NATO bombing of Yugoslavia . On January 18 , 1999 , the FR Yugoslavia government made him persona non grata . A week later , on the intervention by European Council and Russian Federation , Prime Minister of FR Yugoslavia Momir Bulatović froze the decision . The mission was discontinued following the end of the Kosovo War in June 1999
Račak massacre
Račak massacre
William Walker (diplomat)