Keeping it secret: surveillance, informant networks, and the protection of informants in authoritarian regimes

Abstract Authoritarian regimes rely heavily on informants to infiltrate and surveil dissident organizations. While the role of informants in state repression is well-documented, existing research often overlooks how secret police use the intelligence gathered from informants without compromising their identities. Here, we examine the conditions under which secret police agencies seek to protect informants from exposure. We argue that agencies face a tradeoff between the risks of exposing informants and the costs of implementing protection, often prioritizing protection for informants who are deeply embedded in dissident networks and provide rare, high-value intelligence. Using declassified surveillance reports from 1970s Taiwan, we find that protection is most likely when informants are close to well-connected dissidents, interact with behind-the-scenes activists, or provide sensitive information about internal conflicts. Deeply embedded informants offer high-value intelligence but face greater risks of exposure, making them especially worth protecting. These findings contribute to research on surveillance and repression by showing how secret police manage the risks of informant exposure while leveraging human intelligence to counter dissent.