International organizations — Personality — Legal personality of organization before courts of non-member States — Immunity — Jurisdictional immunity and immunity from execution — Legal basis for right of international organizations to invoke immunity — Whether requiring international agreement to which forum State is a party — Whether regional international organizations enjoying “objective international personality” binding on third States — Economic Community of West African States (“ECOWAS”) — Deposit of funds with Bank of Credit and Commerce International — National authorities putting Bank into liquidation and freezing accounts — Whether constituting measure of execution against international organization — Claim for repayment of funds by ECOWAS — Whether constituting waiver of immunity — The law of France