An Issue for All Seasons: Peacetime Espionage and International Law

Abstract

Spies have always had a role in human history. Nevertheless, International Law seems to present a legal grey area that makes particularly difficult to ascertain the legitimacy of espionage and its regulation. The aim of this article is to assess and reconstruct the regulation of secret services’ intelligence collection activities towards States in the context of the Jus Gentium from the substantial point of view represented by both customary and conventional law. Furthermore, it will analyse the reasons behind the denial of the functional immunity to captured spies before domestic jurisdictions.