The court discusses the conditions under which a party may be estopped from raising a ground for refusal of enforcement under the Convention or has waived the right to raise it.

Due process: The court discusses various irregularities affecting due process, including letters not sent, names of arbitrators or experts not communicated, language of proceedings and communications, etc.

Public policy: The court discusses the meaning of (international as compared to domestic) public policy, generally defined as the basic notions of morality and justice of the enforcement State.