Stephen Costello is a non-resident fellow at the Quincy Institute and a non-resident scholar at the Institute for Korean Studies at George Washington University. Since 1990 he has been a political consultant, policy analyst, columnist and facilitator of U.S.–Korea dialogue. Working mainly in Washington and Seoul, Costello has run think tank programs and consulted with companies, embassies, government officials and former officials, academics and scholars in both capitals. During these three decades he has maintained regular contact with civic groups, politicians and journalists focusing on the urgent pending issues in Korea, on the Peninsula, and in the East Asia region. He has also chronicled the shifting U.S. policies toward the region. From 1989–95 Costello was a consultant to overseas political parties and foundations at Gowran International. From 1995–98 he was Director of the Kim Dae-jung Peace Foundation/Washington office. From 1999–2004 Costello was Director of the Korea in Transition program at the Atlantic Council in Washington, D.C.

He has been a speaker at universities in Washington and Seoul and several times at Syracuse University, his alma mater. Costello has also spoken to groups at the U.S. State Department Intelligence & Research, U.S. National Intelligence Council, Korean Foreign and Unification ministries, and the Korean National Intelligence Service. Some of Costello’s writings can be found at the East Asia Forum, a project of Australia National University in Melbourne (https://eastasiaforum.org/author/stephen-costello/), and at The Korea Times, the oldest English language paper in Korea. (https://www.koreatimes.co.kr/www2/common/search.asp?kwd=Stephen%20Costello).