International political outcomes are deeply shaped by the balance of power, but some military capabilities rely on secrecy to be effective. These “clandestine capabilities” pose problems for converting military advantages into political gains. If clandestine capabilities are revealed, adversaries may be able to take steps that attenuate the advantages they are supposed to provide. On the other hand, if these capabilities are not revealed, then adversaries will be unaware of, and unimpressed by, the real balance of power. Most of the existing literature emphasizes that states have few incentives to signal their clandestine capabilities. This conclusion deserves qualification: the condition of long-term peacetime competition can make signaling a profitable decision. Within this context, two important variables help determine whether a state will signal or conceal its secret capabilities: the uniqueness of the capability and the anticipated responsiveness of the adversary. An extended case study of Cold War strategic antisubmarine warfare confirms these predictions.