After the election of 1998 Voorhoeve wasn't offered a position in the new cabinet (which would later fall after a report of the Srebrenica massacre) and returned to the House of Representatives on 19 May 1998 serving again as frontbencher and spokesperson for Kingdom Relations. In November 1999 Voorhoeve was nominated as a Member of the Council of State serving from 1 December 1999 until 1 January 2011, and worked as a distinguished professor of International relations and War studies at the Royal Military Academy and the Royal Naval College from January 2001 until January 2011.