This Article will focus on the narrower questions of whether obtaining secret intelligence-that is, without the consent of the state that controls the information-is subject to international legal norms or constraints, and what restrictions, if any, control the use of this information once obtained. Traditional approaches to the question of the legitimacy of spying, when even asked, typically settle on one of two positions: either collecting secret intelligence remains illegal despite consistent practice, or apparent tolerance has led to a "deep but reluctant admission of the lawfulness of such intelligence gathering, when conducted within customary normative limits.” Other writers have examined possible consequences in terms of state responsibility of intelligence activities that may amount to violations of international law. Given the ongoing importance to states of both intelligence and counterintelligence, such issues may never be resolved conclusively. There is little prospect, for example, of concluding a convention defining the legal boundaries of intelligence gathering, if only because most states would be unwilling to commit themselves to any standards they might wish to impose on others.
The Spy Who Came in From the Cold War: Intelligence and International Law,
Mich. J. Int'l L.
Available at: https://repository.law.umich.edu/mjil/vol27/iss4/2