Covert Communication: The Intelligibility and Credibility of Signaling in Secret

Can states credibly communicate their intentions through covert policy tools, despite the absence of credibility-enhancing publicity? Most extant research suggests covert action and secrecy in general are uniquely uninformative and often used as an alternative to signaling. Yet episodes such as Richard Nixon's secret bombing of Cambodia suggest that leaders have used covert action to convey intentions and coerce adversaries. This article builds a theoretical framework for understanding signaling in the covert sphere, developing reasons why states find covert communication both intelligible (that is, the basic intended message is understandable) and credible (that is, the message is believable). We argue that two target audiences—local allies and strategic adversaries—tend to observe covert action and that the costs and risks incurred by initiating and expanding covert action credibly convey resolve. We assess our arguments empirically through careful process tracing of a set of nested covert interventions by Soviet and American leaders in conflicts in Angola and Afghanistan. Drawing on a trove of recently declassified material, we assess intentions and inferences related to covert signaling. We find that both strategic adversaries and local partners observed and drew inferences about resolve. Covert lethal aid programs thereby served as a credible indicator of resolve through three mechanisms we identify in the paper: sunk costs, counter-escalation risks, and domestic political risks. These findings have important implications for the study of coercive bargaining, secrecy, and reputation. They also shed light on an important policy tool contemporary policymakers will likely use, suggesting the kinds of effects covert action has and elucidating the basic interpretive framework needed to communicate messages with new methods like covert cyber attacks.