This article explores the challenges of implementing UN Security Council Resolution 1540 through the prism of the “tragedy of the commons.” Because implementing 1540 requires a significant investment of time and resources, the decision by states not to implement the resolution is a rational inaction for each individual state driven by self-interest to maximize private gains. However, this ultimately leads to collective irrationality and the destruction of the public good, i.e., common security, leaving every state worse off.