Sovereign immunity: Rule, comity or something else?

Abstract

Sovereign immunity is best understood not as a specific rule of customary international law, but as a legally binding principle. If not bound by detailed treaty obligations, states are free to frame and define the scope and limits of sovereign immunity within their legal orders as long as they observe the boundaries set by other principles of international law. Viewing sovereign immunity as a principle provides for a much better explanation of the still diverse state practice than the currently prevailing concept that conceives immunity as a rule of customary international law and its denial as an exception to that rule. The distinction between principle and rule also has far-reaching practical implications. Instead of asking whether state practice allows for a certain exception, the focus must be on the limits that international law prescribes. States therefore enjoy much greater liberty to define the limits and scope of sovereign immunity, even though this liberty is restricted. © EJIL 2011; all rights reserved.