At times he has held teaching and oversight positions at various colleges and universities : Columbia University 's School of International and Public Affairs ( 1990 @-@ 1994 ) ; Linowitz Chair of International Studies , Hamilton College ( 1993 ) ; Trustee , Dartmouth College ( 1992 @-@ 2002 ) , Chairman of Board of Trustees , ( 1996 @-@ 1999 ).
