Containerized shipping has always been an attractive target for thieves and smugglers--and now terrorists. Are today's security measures working or not? This report lays out a framework for assessing the effects of supply-chain security proposals. 450-character abstract: Much worldwide cargo, from raw materials to finished products, travels via containerized shipping. For the shippers, the main concern has always been losses from theft or accident. But shipping containers are as attractive to terrorists as they are to thieves and smugglers. New security measures have therefore proliferated. This report defines a framework for assessing the effects of these measures, reviews the balance of current container security risk-reduction efforts, and lays out directions for further research.