Major General Karol John Drewienkiewicz was born in the United Kingdom in 1946. He was Deputy Head of Mission and Chief of Operations of the OSCE Kosovo Verification Mission, in Kosovo, during the time leading up to the NATO Bombardment in 1999. According to globalpublicpolicy.net 
Maj Gen John Drewienkiewicz was commissioned into the Royal Engineers in 1966 and studied engineering at Sidney Sussex College Cambridge. He served in Germany, Denmark, Canada, the Gulf and the UK, becoming the Chief Engineer of the British Army in 1994. Selected to be the Chief of Staff of the NATO SFOR Headquarters, he formed and trained this new unit in mid 1996. He deployed to Sarajevo in Oct 1996, remaining there until Aug 1997. He then served as Military Advisor to the High Representative Jan to Aug 1998. In Oct 1998 he moved to Vienna at 6 hours notice to plan the unarmed OSCE Kosovo Verification Mission, subsequently moving to Pristina as the KVM's Chief of Operations. He remained through the violent winter of 98/99, until the KVM was ordered to leave on 20 Mar 1999. He returned to Pristina with KFOR in mid Jun. Since retiring from the Army in early 2001 he has remained connected with the Balkans. In 2002 he spent 8 months with the OSCE in Sarajevo assisting with the downsizing of the entity armed forces. In late 2003 he returned to Sarajevo to assume the triple hatted post of Military Advisor to the High Representative, Vice Chair of the Defence Reform Commission, and Director of the OSCE's Department of Security Cooperation. The Defence Reform Commission having completed its work of developing the unified Armed Forces of BiH, he returned to the UK in Dec 2005. Drewienkiewicz gave evidence for the prosecution in the trial of Slobodan Milosevic on 12 April 2002 
Sarah d'Adda, writing in Giornale del Popolo,  cited a colleague:
"Nor was it the European diplomats who headed the different departments. It was 'The Fusion', a section in the headquarters of the OSCE in Pristina. It was under the direction of British general John Drewienkiewicz, one of the vice directors of the mission. Officially, he was in charge of co-ordinating security. In reality, no one knew with any certainty what his responsibilities were. (. . .) Little by little we came to understand that this was a center for the co-ordination of information going into the hands of American and British military personnel."