Over 39 years in the US Army, commander and staff of the U.S. Army and deployed in several combat operations.
The 32nd Commanding General of the 8th U.S. Army in Korea from 2013 to 2016.
Establishing U.S. Branch and leading the US business for four years after he joined Hanwha Group in 2017.

The Director of SIPRI's Arms Trade and Transfers Program.
A former Head of Aerospace, Defense, and Security at Global Data.
Main Research: Geopolitics, maritime security, comprehensive security research, etc.

Professor in the Department of Political and International Studies at Chung-Ang University.
The Vice President of the Korean Association of International Politics and as a policy advisory committee member for the Ministry of Foreign Affairs.
Main Research: "Leading Nations and Just Transition: Direction of South Korea's State Affairs in the Post-COVID Era"; "Geopolitical Risks and Economic Security in the Age of U.S.-China Strategic Competition"; etc.

Professor in the Department of Political Diplomacy at Ajou University.
Advisory committee member in multiple government departments including the Ministry of Foreign Affairs, Ministry of Trade, Industry and Energy, and Ministry of Science and ICT.
Main research: “Strategic Competition between the U.S. and China: What Is the Problem and How to Solve It’ (2020)”; “Multi-Dimensional Diplomacy of China during the Biden Era' (2021)”; etc.

Professor at the Department of International Studies, Scranton College, Ewha Womans University.
Policy advisor for the Ministry of Unification and an advisory member for North Korean human rights investigations at the Ministry of Unification.
Main research "U.S. Indo-Pacific Strategy and the ROK-U.S. Alliance (2022)"; “U.S. Indo-Pacific Strategy and the ROK-U.S. Alliance: Integrated Deterrence and Global Posture Review(GPR)”; etc.

Director of Armaments and Communications-Electronics Directorate USNATO in Brussels, Belgium
Appointed as a Senior Executive Service in 2013, after serving 21 years as an Artillery officer in the U.S. Army.
Director of International Cooperation at the Office of the Undersecretary for Acquisition, Technology, and Logistics (AT&L and A&S) (2013-2016).

Future G, Office of the Under Secretary of Defense for R&E.
Vice president of the Korean War Veterans Memorial Foundation
A former director of 5G operations in the OUSD for R&E

Professor at the Business School at Yonsei University.
Honorary President of the Korean Production Management Association and the Vice President of the Korean Management Association.
Main research: “global supply chain strategies”; “Supply network structure analysis”; “Smart manufacturing and smart supply chain research”; etc.