Studies and early career Kohnstamm attended a
gymnasium in
The Hague from April 1962 until May 1968 and applied at the
University of Amsterdam in June 1971, majoring in Law and obtaining a
Bachelor of Laws degree in June 1973. He worked as a student researcher before graduating with a
Master of Laws degree in July 1977. Kohnstamm worked as a
criminal defense lawyer in Amsterdam from October 1977 until June 1981.
House of Representatives Kohnstamm was elected to the
House of Representatives after the
1981 general election, taking office on 10 June 1981 serving as a
backbencher. After the
1982 general election Kohnstamm was not re-elected and he continued to serve until the end of the parliamentary term on 16 September 1982. Kohnstamm again worked as a criminal defense lawyer in Amsterdam from September 1982 until June 1986. Kohnstamm served as chairman of
Democrats 66 from 30 October 1982 until 20 May 1986. After the
1986 general election, Kohnstamm returned to the House of Representatives, taking office on 3 June 1986 serving as a
frontbencher as spokesperson for the interior, justice, law enforcement, health, the civil service and abortion and deputy spokesperson for foreign affairs, European affairs and the
Benelux Union. He also chaired the parliamentary committee for law enforcement and the parliamentary committee for the Ombudsman.
State Secretary for the Interior After the
1994 general election, Kohnstamm was appointed as
State Secretary for the Interior in the
first Kok cabinet, taking office on 22 August 1994. He was tasked with public security, emergency services, emergency management and urban planning. In December 1997 Kohnstamm announced that he would not stand for the
1998 general election. Following the
cabinet formation of 1998, Kohnstamm asked not to be considered for a post in the
new cabinet; the first Kok cabinet was replaced by the
second Kok cabinet on 3 August 1998.
Late career Kohnstamm remained in active in national politics; he was elected to the
Senate after the
1999 Senate election, taking office on 8 June. He served as spokesperson for foreign affairs, justice, health, European affairs, art and culture, and chaired the special parliamentary committee for the European Court of Justice. He left the Senate on 7 September 2004. He was the chair of the Dutch Data Protection Authority from 2004 to 2016. From 2016 tot 2021 he was the chair of the Euthanasia Review Committee. From 2021 to 2023 he chaired the Restitution Committee that gives recommendations and binding opinions concerning Nazi looted art. He also was chair of board of the International Chamber Music Festival Schiermonnikoog (2012-2021) and of the board of the foundation Forbidden Music Regained (2014-2021). ==Decorations==