In 2008–2009 he held the seat of distinguished visiting Goodhart Professor at the Faculty of Law, Cambridge University.
He served in the Finnish Diplomatic Service in the years 1978–1996, lastly as director of the Division of International Law.
It asserts that international law is vulnerable to criticisms of being either an irrelevant moralist utopia or an apology for Realpolitik.
[citation needed] The Gentle Civilizer of Nations: The Rise and Fall of International Law 1870–1960 (2001; ISBN 978-0521548090) has two agendas.
The second is to offer a sociology of the profession of international law, using biographical studies of Hersch Lauterpacht, Carl Schmitt and Hans Morgenthau.