Marc Weller

Marc Weller

About/Bio

Marc Weller is the Director of the Centre for Global Governance and Security, and of the International Law Programme, at Chatham House. He is Professor of International Law and International Constitutional Studies in the University of Cambridge and the former Director of the Lauterpacht Centre for International Law and of the European Centre for Minority Issues. He also served as Senior Mediation Expert in the UN Secretariat.

Recently Published

The US Sanctions Against the ICC

October 15, 2026

Some two hours after the Nobel Prize Committee announced the award of the Peace Prize to Navi Pillay for her work on international law and the establishment of international accountability for atrocity crimes, the US government struck back.  Secretary of State Marco Rubio announced a significant escalation in the US campaign against the International Criminal…

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The Davos Trap on Greenland

January 23, 2026

The dispute about Greenland has been conducted by the US as a zero-sum game. Either ‘ownership’ over Greenland would be handed over to Washington, or else economic sanctions or worse would be applied to Denmark and her European allies. It was all or nothing until earlier this week.  There is a general sense that NATO…

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Time for another Ukrainian Genocide Case?

February 6, 2024

In his as ever instant and persuasive reporting and analysis, Marko Milanovic has drawn attention to the rather unusual and, presumably for Ukraine, unexpected result in the jurisdictional phase of the Ukraine/Russian Federation genocide case. The case appears to reverse the thrust of the Preliminary Measures Order decided by the ICJ just weeks after the invasion…

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Popular articles by Marc Weller

Secession and Self-determination in Western Europe: The Case of Catalonia

October 18, 2017

This presentation is based in part on the Legal Opinion by an International Commission of Legal Experts addressing the question of Catalonia: The Will of the People and Statehood. The Commission was composed of Professors Marc Weller (UK ), John Dugard (South Africa), Richard Falk (USA) and Ana Stanic (Slovenia). Although the Opinion was commissioned by Esquerra…

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Russia’s Recognition of the ‘Separatist Republics’ in Ukraine was Manifestly Unlawful

March 9, 2022

The rush to judgment can be deceptive. A recent contribution to these pages cautions us against making instant assumptions of fact and law when considering Russia’s recognition as states of parts of Luhansk and Donetsk Oblasts within Ukraine as manifestly unlawful. Two questions arise: Do the Oblasts meet the criteria of statehood and, if so,…

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Does the ICJ have the Legal Authority to Pronounce itself on the Right to Self-Defence?

January 10, 2024

Jesse Lempel raises a profound issue in his recent post concerning the South African application for provisional measures against Israel in the Gaza genocide case. He asserts that the International Court of Justice, the principal judicial organ of the United Nations, cannot ‘order provisional measures that impair a state’s right to self-defence.’ The argument appears to be…

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Related Topics

Arrest Warrants Crimes Against Humanity Genocide International Criminal Court International Criminal Law International Tribunals Iraq Jurisdiction Myanmar Palestine Russia Sanctions United States Universal Jurisdiction War Crimes Armed Conflict Borders Dispute Resolution Greenland NATO Self-Determination States and Statehood Territorial Disputes Threat of force Use of Force International Court of Justice Ukraine

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