ADST Staff


staff_johnson_susan_sm01President – 
Susan Rockwell Johnson is a career member of the Senior Foreign Service with over three decades of distinguished service and serves as the President of ADST.  She served in a broad range of bilateral and multilateral assignments in and out of the State Department including in Bosnia as Deputy High Representative and Supervisor of Brcko District, in the Coalition Provisional Authority in Baghdad as the Senior Advisor to the Iraqi Foreign Ministry, as Deputy Chief of Mission and Charge d’affaires in Romania and Mauritius, as well as in Russia, Cuba, Pakistan, the United States Mission to the United Nations, several assignments in the State Department, on the Hill and with the National Endowment for Democracy. As the elected President of the American Foreign Service Association (AFSA) from 2009 to 2013, Ms. Johnson focused on the Foreign Service labor-management issues key to the Foreign Service. Following her two terms as AFSA President, Ms Johnson was detailed to the American Academy of Diplomacy as a Senior Advisor to provide her expertise and work on the Academy’s recently released report “American Diplomacy at Risk”.Prior to entering the Foreign Service, Ms. Johnson worked in the private sector in the areas of strategic planning, international marketing and joint venture negotiation.  She has a B.A. in History (Summa cum Laude) from Principia College and an M.A. in International Relations from the Johns Hopkins School of International Studies (SAIS).  She is married to Ambassador Riaz M Khan, retired Pakistani diplomat and former Foreign Secretary of Pakistan.  She serves on the Boards of the Diplomacy Center Foundation and the Chestnut Hill Benevolent Association in Boston, Massachusetts.

Executive Director – Nathan Holt
 was named executive director of the Association for Diplomatic Studies and Training (ADST) in 2017. Prior to joining ADST, Holt was interim Deputy Chief of Mission and charge d’affaires at our Embassy in Bamako, Mali.  From 2015 to early 2017, Holt was  deputy director in the Office of West African Affairs at the U.S. State Department.  His unit had principal responsibility for Nigeria, Africa’s most populous country and second largest economy.  From 2012 to 2015, Holt was the Senior Foreign Policy Advisor to the Commander of the United States Africa Command (AFRICOM), based in Stuttgart, Germany.  In that capacity, he travelled to more than 40 countries in Africa and Europe, ensuring that AFRICOM’s efforts were consistent with U.S. policy and well-coordinated with our partners.  A career officer in the United States Foreign Service, Holt previously served as Deputy Principal Officer at the United States Consulate in Cape Town, South Africa (2009-11) and Deputy Chief of Mission at the U.S. Embassy in Libreville, Gabon (2007-09).  Holt has served as a consular officer in Senegal, a public affairs officer in Cape Town, and a political officer in Gambia, Kenya and Uganda.  From 2006 to 2007 he was part of the first team of U.S. personnel opening a consulate in Juba, South Sudan.  He has served as charge d’affaires at four different posts

Prior to becoming a diplomat, Holt was Executive Director of the United States-Angola Chamber of Commerce (1994-95).  A lawyer, Holt practiced international trade law in Washington, D.C.  He has also worked as a research assistant at the World Bank and as news editor of a weekly newspaper.  As a Peace Corps volunteer in Botswana (1980-83) he worked for a development bank and for Botswana’s Ministry of Finance.  Holt earned a juris doctor degree from the University of Virginia, and a master of arts in African History from Northwestern University.  He received an undergraduate degree in History, magna cum laude, from Boston College.  He has published in the Virginia Journal of International Law, and has authored or co-authored opinion pieces in the New York Times and the Wall Street Journal.  Holt has received five individual Superior Honor Awards from the U.S. State Department, and the Joint Meritorious Civilian Service Award from the Department of Defense.


IMG_4696Oral History Director – Charles Stuart Kennedy has been director of the Foreign Affairs Oral History Program since its inception in 1985. A career officer in the US Foreign Service from 1955 to 1985, he retired with the rank of Minister Counselor. Mr. Kennedy was consul general in Naples, Italy (1979-81), Seoul, South Korea (1976-79), Athens, Greece (1970-74) and Saigon, South Vietnam (1969-70). He was educated at Williams College (BA) and Boston University (MA). He is the author of The American Consul: A History of the United States Consular Service 1776-1914, and co-author of The U.S. Consul at Work and American Ambassadors in a Troubled World. He was awarded the Foreign Service Cup from the Director General of the Foreign Service in 1997 for his work as an oral historian. In June 2014 the American Foreign Service Association (AFSA) gave him the Award for Lifetime Contributions to American Diplomacy in recognition of his distinguished Foreign Service career and a lifetime of public service. Previous recipients of this prestigious award include George H.W. Bush, Lawrence Eagleburger, Cyrus Vance, Thomas Pickering, George Shultz, and Richard Lugar. In 1986, after retiring from the Foreign Service, Stu became managing director of The George Washington University’s Foreign Service History Center. There he created the Foreign Affairs Oral History Collection and began recording the insights and experiences of American diplomats. The program moved to Georgetown University and then, in 1988, to ADST. In that capacity, he has personally interviewed more than 1,000 retired American diplomats, some of whose careers date back to the 1920s.


Deputy Oral Historian –  Mark Tauber completed a career in the U.S. Foreign Service in 2013 divided evenly between political affairs and public diplomacy.  As a Political Officer, Mark worked on refugee issues in Central America, conventional arms control in Europe at the OSCE, and in Armenia, on the Nagorno-Karabakh dispute.  In Public Diplomacy, Mark received Meritorious Honor Awards for his work as a Cultural Officer in Romania and Hungary.  In Costa Rica, as Public Affairs Officer, he expanded Embassy San Jose’s Facebook followers from 2500 to 150,000, began use of Twitter — reaching 10,000 followers in two years, and introduced live streaming of Embassy events.  During his final year as Director of the Office of American Spaces in the State Department, Mark authored an article on the history of American cultural/educational centers.  Before joining the staff of ADST in 2016, Mark received his teaching certification from the Commonwealth of Virginia in 2014 and served as a volunteer instructor with the Literacy Council of Northern Virginia.  Mark’s degrees are in Diplomatic History (B.S., 1981) and Business Diplomacy (M.S., 1984) from Georgetown University.  He was also awarded a Master’s Degree in National Security Resourcing from the Industrial College of the Armed Forces.  Mark speaks Spanish and French.


Oral History Manager – Marilyn Bentley joined the ADST staff in February 1997. She has a B.S. from Northeastern University. As a Foreign Service spouse she accompanied her husband on tours to Doha, Qatar; Amman, Jordan; Dar es Salaam, Tanzania; and Jeddah, Saudi Arabia. She oversees ADST’s oral history program and assists in the publication program and administering grants obtained for the Foreign Service Institute. She spearheaded digitizing ADST’s oral history cassette recordings, adding ADST’s oral histories to our website, and integrating the Foreign Service spouse oral histories into ADST’s Foreign Affairs Oral History Collection. Mrs. Bentley is co-editor of Frontline Diplomacy: The U.S. Oral History Collection on CD-ROM.


img_3937Office Manager – Karen Mehring joined ADST in January 2016. She has a BA from California State University, Chico, in History and was Director of the Folsom History Museum from 2001 to 2008. In 2008, her husband Daniel joined the State Department as a Foreign Service Officer. They have lived in Abuja and Rome and currently reside in Reston, Virginia with their daughter and two cats.  At ADST, Karen is responsible for day-to-day business management, including financial accounts, membership, tax, payroll and budgetary matters; sundry shop sales; and processing of book sales.





margeryPublishing Director – Margery B. Thompson directs ADST’s book-related programs, advises diplomats and others on editing and publishing matters, and coordinates the ADST-DACOR Diplomats and Diplomacy Series. Before joining ADST in 1995, she was director of publications and editor at the Georgetown University Institute for the Study of Diplomacy (ISD) from 1980 to 1994. At ISD she was coeditor and compiler (with Smith Simpson) of Education in Diplomacy: An Instructional Guide (ISD/University Press of America, 1987) and editor of As Others See Us: United States Diplomacy Viewed from Abroad (ISD, 1989) and Beacons: Great Teachers of the Georgetown School of Foreign Service (SFS/Georgetown University, 1994). She collaborated with ISD authors and publishers in the development, editing, and publication of many other ISD books, reports, and monographs and is now doing the same for ADST. Her previous appointments included the Institute of International Education, the Brookings Institution, the University of Pittsburgh Center for Regional Economic Studies, and the Pittsburgh Commission on Human Relations. She was educated at Northwestern University, the University of Pittsburgh, and George Washington University.


Senior Fellows

Carlton McLellan

Carlton McLellan ([email protected] ) is Managing Director of Global Ties U.S. and founder and President of the nonprofit consulting firm MYinternational, Inc. His PhD is in international education policy studies from the University of Pretoria, South Africa. He also holds a Master’s degree in international and development education from the University of Pittsburgh and a Bachelor’s degree in international studies from Ohio University in Athens, Ohio. His work with ADST will focus on educating, celebrating, and critiquing the lives and impacts of Black Americans who have held the rank of U.S. Ambassador, and also building the ADST’s Bunche Legacy Project, which seeks to educate the public on the important contributions of Black/African Americans to U.S. diplomacy and foreign affairs.


Former ADST Presidents

Chris Sibilla, 2015-2016
The Honorable Kenneth L. Brown, 2001-2014
The Honorable Edward M. Rowell, 1997-2001
The Honorable Stephen Low, 1992-1997
The Honorable Thomas Boyatt, 1989-1992
The Honorable Richard B. Parker, 1986-1989

Former ADST Executive Directors

Judith Baroody, 2015-2017
Chris Sibilla, 2012-2015
James Warren, 2011–2012
John Naland, 2010-2011
Vicente Valle, 2009-2010
Les McBee, 2007-2009
Dan Whitman, 2006-2007
Marilyn Bruno, 2006
Jack Zetkulic, 2004-2006
Veda Engel, 2002-2004
LW Koengeter, 2000-2002
John Miller, 1999-2000
Richard Jackson 1998-1999
Dennis Kux 1993-1994
Eugene Bovis 1987-1988