State Responsibility
Lieber Institute White Paper: Responding to Malicious or Hostile Actions under International Law
Recent consultations with senior legal advisers have highlighted the need for a clear map of response options available to States facing hostile or malicious actions, whether attributable to another State or a non-State actor. After all, to respond effectively to such...
The ICJ’s Provisional Measures Order: Unprecedented
On March 16, 2022, the International Court of Justice (ICJ) rendered its provisional measures order in the application brought by Ukraine against Russia under the Genocide Convention, arguing, inter alia, that Russia’s invasion was an unlawful abuse of its obligation...
Ukraine’s Legal Counterattack
Beyond its endurance on the battlefield, Ukraine has launched a legal counterattack against Russia in the courts. The normally slow-moving, process-heavy gears of international justice are now moving at relative lightspeed in response to Russia’s illegal invasion of...
On War
As the invasion of Ukraine was starting, the Russian Ambassador to the United Nationals responded to the Ukrainian Special Envoy “Don’t call this a war. This is called a ‘special military operation in Donbass.’” Other Russian Ambassadors reiterated the statement...
Over-the-Horizon Operations – Part III: How May Force Be Used?
Part I of this series examined when the United States may lawfully resort to force in the form of over-the-horizon (OTH) operations, a question that looms large given President Biden’s July announcement that the United States is developing the capability in light of...
Over-the-Horizon Operations – Part II: Where May Force Be Used?
Part I of this series examined the issue of when the United States would enjoy a legal right to conduct over-the-horizon (OTH) operations. It identified three bases for such operations: UN Charter Chapter VII authorization or mandate, self-defense, and request from...
Over-the-Horizon Operations – Part I: When May Force Be Used?
Responding in early July to concerns about the withdrawal of troops from Afghanistan after two decades of war, President Biden announced, “We are developing a counterterrorism over-the-horizon capability that will allow us to keep our eyes firmly fixed on any direct...
Mercenaries on the Battlefield: What Legal Advisors Must Know
Mercenaries … are useless and dangerous. And if a prince holds on to his state by means of mercenary armies, he will never be stable or secure… -- Niccolò Machiavelli, The Prince Mercenaries have been used since the dawn of war. In recent years, however, there has...