The Sempra annulment decision of 29 June 2010 and subsequent developments in investment arbitration dealing with the necessity defence

On 29 June 2010, an ad hoc International Centre for Settlement of Investment Disputes (ICSID) Annulment Committee annulled the 2007 Sempra Award for manifest excess of powers (within the meaning of the ICSID Convention), as it found that the Tribunal had failed to apply the correct law. The decision took into account the measures adopted by the Argentine Government to face the 2001 economic and political crisis and (like other previous awards and decisions on similar cases) raised the issue of the interpretation and application of the necessity defence in situations of economic emergencies. The approach of the ad hoc Committee on this particular point is the main focus of this note.