International relations, sustainable development, and the science of science were also areas of his research.
He edited six collections of papers in physics and two in international relations. He was an invited lecturer at 57 international conferences and organized 18 international conferences. He was principal investigator on projects of the IAEA, EU, and NSF (USA), and twice, in 2005 and 2008, director of NATO workshops. He served as a reviewer for EU Framework 5, 6, and 7 projects, as well as for NSF and DOE projects in the USA and Croatia.
He was an honorary member of the American Physical Society. He was a professor (visiting professor) at the University of California, Los Angeles, USA (1964–2003), Georgetown University, Washington, DC (1972–1994), Duke University, North Carolina (1980–present), Free University, Amsterdam, the Netherlands (1974), Université Louvain, Louvain-la-Neuve, Belgium (1975), Kyoto University, Japan (1981), and an advisor at Los Alamos National Laboratory, Los Alamos, New Mexico (1972–2002), the Naval Research Laboratory, Washington, DC (1973–1980), the Jožef Stefan Institute and the Jožef Stefan International Postgraduate School, Ljubljana (1996–present).
In 1977 he was elected Associate Member of the Croatian Academy of Sciences and Arts, and in 1991 Full Member. That same year he became President of the HAZU Committee for International Cooperation. During his presidency, HAZU became a member of the International Council of Scientific Unions (ICSU), international and European associations of scientific societies, the association of European academies of sciences and arts (ALLEA), and the global associations of academies (IAP and IAMP).
From 2000 to 2003, Šlaus was a member of the Croatian Parliament, serving on the Committee for International Relations and the Committee for Education, Science, Culture, and Sport. In 1997 he co-founded and served as Secretary General of the Croatian Movement for Democracy and Social Justice. He was a co-founder and member of Academia Europaea (since 1988), President of its Committee for Physics and Technical Sciences (1990–1994), a member of Academia Scientiarum et Artium Europaea in Salzburg (since 1992), a member of the World Academy of Art and Science (WAAS) since 1994, its President from 2011 to 2013, and currently its Honorary President. Since 2005, he has been a member of the WAAS Presidency and was President for Southeast Europe. He founded and was Editor-in-Chief of the WAAS journal Cadmus. He was an honorary member of New Westminster College, Vancouver, Canada, a foreign member of the Macedonian Academy, a corresponding member of the Montenegrin Academy, and a member of the Croatian Academy of Medical Sciences.
He was a member of the International Council for Science Policy Studies, a member of the World Innovation Forum, a member of the UNESCO Task Group for Revitalizing R&D in Southeast Europe, and co-founder and President of the International Center for Sustainable Development in Ljubljana. Since 2002 he was also a member of the International Council of Pugwash Conferences on Science and World Affairs, as well as a member of the Honorary Committee and panelist at the international conference Religion, Science and the Environment.
Since 1987 he had been a member of the Club of Rome, and in 1993 he founded and became President of the Croatian Association of the Club of Rome. Academician Ivo Šlaus received the Ruđer Bošković Award in 1962 and 1969, and in 2008 he received the State Lifetime Achievement Award. He was Dean of the Dag Hammarskjöld College of International Relations and Diplomacy, Zagreb, and a member of the editorial board of International Studies since 2013.
