Mark A. Clodfelter

Senior Counsel

Direct: 202.677.4958
Washington
2100 Pennsylvania Avenue NW
Suite 350S
Washington, District of Columbia 20037

Biography

Mark is senior counsel in the International Dispute Resolution practice, focusing on international arbitration, investment treaty disputes, cross-border litigation, and complex international transactions. With more than 40 years of experience in both government and private practice, Mark represents sovereign states, multinational companies, individual investors, and business enterprises navigating high-stakes international disputes and investment matters. He is widely recognized for his work in investor-state arbitration, state-to-state disputes, and international commercial arbitration, helping clients protect public policy decisions and investments, resolve cross-border conflicts, and manage risk in complex global markets.

Clients turn to Mark when disputes threaten significant government interests, international investments, or commercial relationships. He has served as counsel and arbitrator before virtually every major international arbitration forum, including the International Centre for Settlement of Investment Disputes (“ICSID”), the Permanent Court of Arbitration (“PCA”), the International Chamber of Commerce (“ICC”), the Arbitration Institute of the Stockholm Chamber of Commerce (“SCC”), the American Arbitration Association (“AAA”), the United Nations Compensation Commission, and the Iran-U.S. Claims Tribunal. His experience spans every stage of a dispute, from pre-dispute strategy and treaty analysis to arbitration proceedings, enforcement actions, and post-award recovery efforts.

Mark’s unique perspective is grounded in his service as the U.S. Department of State’s Assistant Legal Adviser for International Claims and Investment Disputes. During his tenure, he led a team of attorneys responsible for protecting the interests of U.S. citizens and companies abroad and represented the United States in numerous international proceedings, including 11 investor-state arbitrations under Chapter 11 of NAFTA and eight state-to-state disputes. Throughout his career, he has represented seven sovereign states and 11 private parties in more than 34 investor-state arbitrations, eight state-to-state arbitrations, and numerous international commercial arbitrations.

In addition to his arbitration practice, Mark advises clients on international trade and investment issues, Cuba claims, import regulations, foreign business operations, sales representation agreements, and Foreign Corrupt Practices Act considerations. His ability to combine strategic legal analysis with a practical understanding of government decision-making helps clients anticipate challenges, evaluate risk, and pursue business objectives across jurisdictions.

A former White House Fellow and recipient of the Presidential Rank Award for Meritorious Service, Mark has been named repeatedly by Washingtonian magazine as one of Washington, D.C.’s top international lawyers. Clients value the blend of government, diplomatic, and arbitration experience, as well as Mark’s ability to guide them through some of the most complex and consequential international disputes. Whether representing sovereign states, global businesses, or investors, Mark delivers practical, business-focused counsel designed to achieve efficient and effective outcomes.

Arbitrator Appointments

  • International Centre for Settlement of Investment Disputes (“ICSID”), former member on the Panel of Arbitrators
  • Kuala Lumpur Regional Centre for Arbitration, former member on the Panel of Arbitrators
  • Arbitrator in six investor-state arbitrations under bilateral investment treaties, including ICSID arbitrations under the Germany-Egypt, Switzerland-Romania, and Spain-Egypt BITs; UNCITRAL arbitrations under the Italy-Romania and Czech-Cyprus BITs; and an ad hoc/PCA arbitration under the China-Mongolia BIT
  • Arbitrator in three international commercial arbitrations under the auspices of the International Center on Dispute Resolution (“ICDR”)
  • Arbitrator in numerous commercial arbitrations under the auspices of the American Arbitration Association (“AAA”)

Related Services

Experience

Investor-State Treaty Arbitrations (Where U.S. is Not a Party)
  • Chevron/Texaco v. Ecuador, PCA CASE NO. 2009-23 (UNCITRAL) Lead counsel (until mid-2021) to the Republic of Ecuador in the damages phase of a landmark investment arbitration under the Ecuador-U.S. BIT arising from a massive environmental litigation. The outcome of the case is a 93.4% reduction in damages, following a liability phase handled by another firm.*
  • Amorrortu v. Peru (UNCITRAL) Lead counsel (until mid-2021) in arbitration under the U.S.-Peru Trade Promotion Agreement (“USPTPA”) relating to a highway construction project. Dismissed on grounds of lack of jurisdiction. *
  • Merck Sharpe & Dohme v. Ecuador (UNCITRAL) Counsel to the Republic of Ecuador in arbitration under the Ecuador-U.S. BIT arising from the alleged treatment of a foreign investor by the Ecuadorean judiciary.*
  • City-State NV v. Ukraine (ICSID) Lead counsel in ICSID arbitration under the Ukraine-Netherlands investment promotion and protection treaty relating to the financial sector. The claimants were awarded a fraction of the damages claimed.*
  • Louis Dreyfus Armateurs v. India (UNCITRAL) Lead counsel to the Republic of India under the India-France BIT concerning the supply and operation of cargo handling equipment in West Bengal. All claims were dismissed on the merits, delivering to India its first-ever victory in an investor-State arbitration. The tribunal awarded India $7.2 million in costs.*
  • Murphy Exploration v. Ecuador (II) (UNCITRAL) Lead counsel to the Republic of Ecuador in arbitration under the Ecuador-U.S. BIT arising from changes in domestic legislation pertaining to the exploitation of oil resources. Secured a 96% reduction in claimed damages.*
  • Repsol YPF v. Ecuador (ICSID) Lead counsel to the Republic of Ecuador in arbitration under the Ecuador-U.S. BIT arising from changes in domestic legislation pertaining to the exploitation of oil resources. The case concluded with a favorable settlement.*
  • Murphy Exploration and Production Company International v. Republic of Ecuador (I) (ICSID) Lead counsel to the Republic of Ecuador in arbitration under the Ecuador-U.S. BIT arising from changes in domestic legislation pertaining to the exploitation of oil resources. Dismissed on grounds of jurisdiction.*
  • Slovak Gas Holding BV, GDF International SAS & E.ON Ruhrgas International GmbH v. the Slovak Republic Co-lead counsel for the Slovak Republic in an ICSID arbitration under the Energy Charter Treaty arising from the regulation of natural gas distribution. Resulted in a settlement favorable to the Slovak Republic.*
  • Achmea B.V. v. The Slovak Republic Lead counsel to Slovakia on intra-EU law issues in an UNCITRAL arbitration under the Slovak Republic-Netherlands BIT arising from alleged measures in the health insurance sector. The case was dismissed for lack of jurisdiction over the investor’s claims. The tribunal also awarded Slovakia €1.35 million in costs.*
  • European American Investment Bank AG (Austria) v. The Slovak Republic Co-lead counsel to Slovakia in an UNCITRAL arbitration under the Slovak Republic-Austria bilateral investment treaty arising from changes in the Slovak health insurance sector. The case was dismissed for lack of jurisdiction over the investor’s claims. The tribunal also awarded Slovakia €1.6 million in costs.*
  • Saint Mary’s VCNA, LLC v. Canada External reader for Canada in a NAFTA Chapter 11 arbitration arising from a proposed development of a quarry in Ontario.*
  • Detroit Int’l Bridge Co. v. Canada External reader for Canada in a NAFTA Chapter 11 arbitration arising from the concession for the Ambassador Bridge between Detroit and Windsor, Ontario.*
  • Sempra Energy International v. Argentine Republic (ICSID Annulment) Counsel in stay proceedings in the defense of award enforcement efforts.*
  • Chevron/Texaco v. Ecuador, PCA Case No. 2007-02/AA277 (UNCITRAL) Lead counsel in a PCA/UNCITRAL arbitration brought by Chevron Corp. alleging denial of justice under seven Ecuadorian court decisions in contract disputes, leading to a 96% reduction in claimed damages.*
  • Protiva v. Islamic Republic of Iran (Iran-U.S. Claims Tribunal) Represented claimant heirs in successful arbitration claims for the expropriation of a Tehran office building.*
  • Ghaffari Islamic Republic of Iran (Iran-U.S. Claims Tribunal) Represented a U.S. principal in successful arbitration claims for the expropriation of his ownership interest in an architectural and engineering firm.*
  • Birnbaum Islamic Republic of Iran (Iran-U.S. Claims Tribunal) Represented a U.S. principal in successful arbitration claims for the expropriation of his ownership interest in an architectural and engineering firm.*
  • Baker International v. Islamic Republic of Iran (Iran-U.S. Claims Tribunal) Represented U.S. oil supply company in a successful arbitration claim for the expropriation of oilfield assets in Iran.*
  • Computer Sciences Corporation v. Islamic Republic of Iran (Iran-U.S. Claims Tribunal) Represented a U.S. technology firm in a successful arbitration claim for the expropriation of rights under a computer services contract.*
  • Development & Resources Corp. Islamic Republic of Iran (Iran-U.S. Claims Tribunal) Represented a U.S. development company in a successful arbitration claim for the expropriation of a project development contract.*
  • Howard, Needles, Tammen & Bergendoff v. Islamic Republic of Iran (Iran-U.S. Claims Tribunal) Represented a major U.S. construction company in a successful arbitration claim for the expropriation of a major highway construction assets.*
  • Bendone DiRossi v. Islamic Republic of Iran (Iran-U.S. Claims Tribunal) Represented a U.S. uniform manufacturing company in a successful arbitration claim for the expropriation of rights under a military supply contract.*
    Representation of the United States in Investor-State Treaty Arbitrations (NAFTA Chapter 11)
    • Glamis Gold Ltd. v. United States (UNCITRAL) Represented the United States against a Canadian mining company alleging regulatory expropriation under federal and California laws.*
    • Canadian Lumber Producers v. United States (UNCITRAL, four cases) Represented the United States in four successful UNCITRAL proceedings, including one first-ever consolidated case, brought by Canadian lumber producers (Canfor, Tembec, and Terminal Forest Products) challenging the application of U.S. antidumping and countervailing duty laws.*
    • Methanex v. United States (UNCITRAL) Represented the United States in successful defense on the merits against a Canadian methanol company regarding legislation banning use of a methanol-based gasoline additive.*
    • Loewen v. United States (ICSID AF) Represented the United States in successful defense on the merits and jurisdiction in a path-setting case arising from allegations of denial of justice.*
    • Canadian Cattle Producers v. United States (UNCITRAL) Represented the United States in successful defense against 109 Canadian cattle producers challenging the closure of the U.S.-Canada border following a mad cow disease outbreak.*
    • Grand River Enterprises Six Nations, Ltd v. United States (UNCITRAL) Represented the United States in successful defense on the merits against a Canadian tobacco company’s claim that the U.S. master tobacco settlement violated the expropriation and national treatment provisions of NAFTA.*
    • Mondev v. United States (ICSID AF) Represented the United States in successful defense on the merits in a case brought by a commercial real estate development company alleging expropriation.*
    • ADF v. United States (ICSID AF) Represented the United States in successful defense on the merits in ICSID Additional Facility proceedings against a construction subcontractor alleging that national content requirements violated the NAFTA Investment Chapter.*
      State-to-State Treaty Arbitrations
      • Republic of Ecuador v. United States (UNCITRAL) Represented Ecuador in arbitration under the state-to-state dispute resolution provisions of the Ecuador-U.S. BIT concerning the proper interpretation and application of the treaty.*
      • Islamic Republic of Iran v. United States (Iran-U.S. Claims Tribunal) Represented the United States government before the Iran-U.S. Claims Tribunal in its defense against Iran’s multi-billion-dollar arbitration claim for compensation for weapons purchased by the Shah’s government from private contractors but not delivered.*
      • Islamic Republic of Iran v. United States (Iran-U.S. Claims Tribunal) Represented the United States government before the Iran-U.S. Claims Tribunal in the defense of an arbitration claim by Iran that the United States violated obligations under the Algiers Accords to arrange for the transfer to Iran of Iranian non-military tangible properties subject to United States jurisdiction.*
      • United States v. Islamic Republic of Iran (Iran-U.S. Claims Tribunal) Represented the United States government in two Iran-U.S. Claims Tribunal cases against Iran regarding Iran’s failure to replenish a $500 million escrow account created to pay arbitral awards against it.*
      • United States v. Islamic Republic of Iran (Iran-U.S. Claims Tribunal) Represented the United States in a claim before the Iran-U.S. Claims Tribunal under the UNCITRAL Rules regarding Iran’s failure to maintain the confidentiality of classified weapons systems information.*
      • United States v. India (UNCITRAL/PCA) Represented the United States government in a UNCITRAL arbitration claim against India before the PCA relating to losses suffered by U.S. companies on a major power plant project recoverable under an investment guarantee agreement.*
      • United States v. Soviet Union/Russian Federation (SCC) Represented the United States in a claim before the Stockholm Chamber of Commerce against the Soviet Union and its successor, the Russian Federation, for the bugging of the new U.S. Embassy in Moscow and other breaches of Embassy construction agreements.*
        International Commercial Arbitration
        • GNPS Consortium v. Iran (ICC) Represented a consortium of American, Canadian, German, and Japanese companies in ICC proceedings against Iran for breach of a contract for construction of a nationwide telecommunications system.*
        • American Energy Company v. Australian Oil Company Represented an American energy investment company claiming royalties from a major Australian oil development company before an ad hoc tribunal in Australia.*
        • American Rice Exporter v. Iraq Represented an American rice exporter in a claim under the U.S. Rice Millers’ Association Arbitration Rules for funds due under a contract with the Government of Iraq.*

        *Representative matters handled while practicing at another law firm.

          Credentials

          Education
          • University of Michigan Law School, Juris Doctor
          • University of Michigan, Master of Arts – Political Science
          • University of Michigan, Bachelor of Arts – Russian and East European Studies
          Admissions
          • State of Michigan
          • District of Columbia
          Associations
            • European Communities Visitors Program

          Recognition

          • Washingtonian, Washington D.C. Top International Lawyer
          • American Bar Association International Law and Practice Section, Outstanding Performance by an International Law Office
          • Presidential Rank Award for Meritorious Service recipient
          • White House Fellow, special assistant to the Under Secretary of State for Political Affairs

          Thought Leadership & Speaking Engagements

          Thought Leadership

          • Co-author with Joseph Klingler, “Reflective Loss and its Limits Under International Investment Law,” C. Beharry (ed) Contemporary and Emerging Issues on the Law of Damages and Valuation in International Investment Arbitration, 2018.
          • Co-author with Diana Tsutieva, “Counterclaims in Investment Arbitration,” Katia Yannaca-Small, Arbitration Under International Investment Agreements: A Guide to the Key Issues (2nd ed., Oxford University Press), 2018.
          • “Written Proceedings in International Investment Arbitration,” Litigating International Investment Disputes: A Practitioner’s Guide, 2014.
          • “Do States Have a Duty to Cooperate in the Interpretation of Investment Treaties?” Proceedings of the Annual Meeting (American Society of International Law), 2014.
          • “The Future Direction of Investment Agreements in the European Union,” Santa Clara Journal of International Law, Vol. 12 No. 1, 2014.
          • Co-author with Francesca Guerrero, “National Security and Foreign Government Ownership Restrictions on Foreign Investment: Predictability for Investors at the National Level,” Sovereign Investment: Concerns and Policy Reactions, 2012.
          • “The Adaptation of States to the Changing World of Investment Protection Through Model BITs,” ICSID Review – Foreign Investment Law Journal, Vol. 24 No. 1, 2009.
          • “U.S. State Department Participation in International Economic Dispute Resolution,” 42 South Texas Law Review 1273, 2001.
          • “The People’s Republic of China and ICSID: Considerations for Prospective Membership,” U.N. Centre on Transnational Corporations, TNC No. 86-129, 1986.

          Speaking Engagements

          • Moderator, “Recent Developments in Investment Arbitrations,” 5th Investment Treaty Arbitration Conference, Prague (October 2015).
          • Speaker, “Do States Have a Duty to Cooperate in the Interpretation of Investment Treaties?” ASIL 108th Annual Meeting, April 2014.
          • Speaker, “The EU’s New Hesitation about Investor-State Arbitration,” Georgetown Law Center Conference on Current Issues in Investor-State Arbitration, February 2014.
          • Speaker, “Shareholder Claims Under NAFTA,” Joint IAI-CIDS-UNCITRAL Conference on Concurrent Proceedings in Investment Disputes, November 2013.
          • Speaker, “Intersections of Human Rights Principles and Investor-State Dispute Resolution,” 11th Annual Harvard Human Rights Journal Symposium, April 2012.
          • Speaker, “The Use of Arbitral Mechanisms in Times of Crisis – Lessons from the Past: The Iran-US Claims Tribunal,” ITA-ASIL Joint Conference, March 2012.
          • Speaker, “Promoting the Use of ADR in Investor-State Treaty Disputes,” World Bank Group Law, Justice and Development Week, November 2011.
          • Speaker, “The Absence of Proper Notification of the Existence of a Dispute or the Non-Observance of the Cooling-Off Period,” Fourth Annual Seminar on International Arbitration, October 2011.
          • Speaker, “The Adaptation of States to the Changing World of Investment Protection Through Model BITs,” 26th AAA/ICC/ICSID Joint Colloquium, November 2009.
          • Speaker, “Top Ten Developments in Investor-State Arbitration,” Georgetown Law Center Conference on Investment Arbitration in Latin America, April 2010.
          • Speaker, “National Security and Predictability for Investors at the National Level,” Vale Columbia Center Third International Investment Conference, October 2008.
          • Lecturer, “Executive Training on Investment Arbitration for Government Officials,” Columbia Center for Sustainable Investment, 2006-2012.
          • Lecturer, “UNCTAD Advanced Training Courses on Managing Investment Disputes,” Columbia Center for Sustainable Investment, 2006-2012.