Intermodal shipping containers carry more than 80 percent of the cargo (as measured in value) moved by ocean liners in international trade. A key virtue of these standardized containers is that they allow for mechanized and automated container handling at transfer points and can be moved readily among modes. The sealed containers are also less vulnerable to cargo pilfering and theft. These virtues have vastly improved the efficiency of ship, train, truck, and terminal operations, reducing the time required for international shipping and enabling more businesses to reduce their warehouse and inventory costs through just-in-time logistics.
In the United States, some 50 ports can handle containers, but only a handful have built a significant business around them because of the large investment required for handling equipment, the need for good connections with highway and rail services, and the economies of scale of warehousing and terminal operations. The three megaports of Los Angeles, Long Beach, and Newark-Elizabeth handle about half of all containers entering and exiting the country. Each of these ports can handle as many as 10,000 containers in a single day.
The U.S. Customs Service maintains inspectors at each port. Their main job is to classify and appraise goods and collect applicable customs duties, although their ancillary functions include the interception of contraband and assistance in enforcing other laws and the regulations of some 40 federal agencies. In most cases, entering containers are cleared with a limited review of documents. Most regular, or “known,” shippers are precleared, and their shipments and documents are not examined by Customs until up to 30 days later, which may be at the end point of their line-haul inland journey by truck or rail. Only about 2 percent of containers are opened and physically inspected at some point in the process. Such inspections are time consuming—they usually delay shipments for several days—and add to the costs of shippers and receivers, who often depend on just-in-time service.
A Threat Scenario
A terrorist purchases a foreign exporter that has a long-standing relationship with U.S. importers. The exporter routinely loads containers at its own facilities. In one of the containers, the terrorist loads a nuclear, chemical, or explosive device that is timed to activate or that can be activated remotely. The container is transported unopened through a foreign transshipment port and is then placed along with thousands of other containers on a large container ship destined for a major U.S. port that handles thousands of containers each day. Recognizing the known shipper, U.S. Customs preclears the container with minimal review of documents. Along with thousands of other containers, it is transferred to line-haul rail for inland transportation to the port of entry into the U.S. economy. The full documentation for the container shipment is scheduled to arrive at the U.S. Customs office within 30 days of the container’s entry into the country.
At any point during this 30-day interval, the deadly device inside can be detonated. Even if intelligence uncovers the plot, there may be no ready way to identify