This book explores the international jurisprudence on Article 79 of the 1980 United Nations Convention on Contracts for the International Sale of Goods (CISG), which is, perhaps, one of its most contentious provisions. The author’s premise is that Article 79—which concerns exemptions for contractual non-performance due to an “impediment” beyond a party’s control—should be interpreted autonomously, that is, as an international norm, without reference to domestic legal concepts and principles. To this end, he considers the application of Article 79 by courts and arbitral tribunals across a number of signatory states.