The complexity of supply chains means that it is difficult to tell where national security arguments begin and end. That may weaken some of the traditional arguments for free trade for the same reasons that we accept the difficulty of rational economic calculation in a socialist society. National security arguments for protectionism may not remain restricted to very small and manageable segments of the economy. Liberals and cosmopolitans will need to pay greater heed to these problems. This essay also considers why complex supply chains may create problems for a carbon tax and for the notion of corporate social responsibility.
