Bitterlich was the Foreign and Security Policy Advisor to Federal Chancellor Helmut Kohl (1993 - 98), then the Ambassador and Permanent Representative of the Federal Republic of Germany to the North Atlantic Treaty Organisation in Brussels, and in the years 1999 - 2002 the Ambassador to Spain. In 2003, he joined Veolia Environnement in Paris as Executive Vice President International Affairs". He is Vice-President of
Notre Europe.