09 Jun 2026
Arnall Golden Gregory Adds Diana Tsutieva and Mark A. Clodfelter to International Dispute Resolution Practice
"Arnall Golden Gregory adds Diana Tsutieva as practice chair and Mark A. Clodfelter as senior counsel in its International Dispute Resolution practice, strengthening investor‑state and cross‑border arbitration expertise."
Diana Tsutieva joins AGG as chair of the International Dispute Resolution practice. She focuses on investor‑state arbitration, commercial arbitration, public international law matters, and cross‑border litigation, and represents clients before leading arbitral institutions including ICSID, UNCITRAL, and the ICC. Her work has encompassed disputes in the energy, mining, financial services, healthcare, waste management, telecommunications, and environmental sectors. Diana has successfully defended European, Eurasian, and Latin American states in investor‑state arbitrations, achieving jurisdictional victories, full victories on liability, and reductions of claimed damages by more than 90%; she has also handled enforcement proceedings in U.S. federal courts under the Foreign Sovereign Immunities Act and the New York Convention. She serves as an arbitrator in international commercial proceedings, advises on public international law issues including investment treaty reform, international trade, and human rights, is active in professional international disputes organizations, and has been recognized in Who’s Who Legal: Arbitration and Lexology: Arbitration as a Future Leader. Diana holds an LL.M. from the University of Paris I: Panthéon‑Sorbonne, a J.D. from Rutgers Law School, and a B.A. from Cornell University.
Mark A. Clodfelter joins AGG as senior counsel, bringing more than 40 years of experience in international commercial disputes. He has served as counsel and arbitrator before ICSID, the Permanent Court of Arbitration, the ICC, the Stockholm Chamber of Commerce, the American Arbitration Association, and in tribunals operating under the UNCITRAL Arbitration Rules, the U.N. Compensation Commission, and the Iran‑U.S. Claims Tribunal. He served for seven years as the U.S. State Department’s Assistant Legal Adviser for International Claims and Investment Disputes, leading matters involving the protection of U.S. citizens and businesses abroad and representing the United States in international arbitration proceedings. His experience includes representation of seven sovereign states, as well as individual and corporate investors, in investor‑state, state‑to‑state, and commercial disputes. Mark has been recognized with awards including the Presidential Rank Award for Meritorious Service, Washingtonian magazine’s recognition as a leading international lawyer, and the American Bar Association’s Award for Outstanding Performance by an International Law Office; he has taught international commercial arbitration at Georgetown Law and holds a J.D., an M.A. in Political Science, and a B.A. from the University of Michigan.