Since the September 11, 2001 terrorist attacks, the United States has been tightening security at the nation's seaports. U.S. officials told a congressional committee earlier this week the task is far from completed.

Every day, 27,000 cargo containers are unloaded at U.S. seaports. That is more than ten million containers a year pouring into the United States from nations spanning the globe. U.S. officials concede that, if terrorists managed to smuggle nuclear materials or biological agents aboard just one container, the results could be catastrophic.

Many local, state and federal entities share duties when it comes to port security. At the federal level, the U.S. Coast Guard plays a central role, as does U.S. Customs and Border Protection, or CBP, which falls under the Department of Homeland Security. CBP Director Robert Jacksta told the Senate Committee on Commerce, Science and Transportation that his agency is taking a proactive approach to weeding out cargo material that could be used in a terrorist plot.

"To meet our priority mission of preventing terrorist weapons from entering the United States, CBP has partnered with other countries on our container security initiative to identify and inspect high-risk cargo at foreign ports before they are shipped to our seaports and pose a threat to the United States," he said.

Under the so-called "Container Security Initiative," U.S. officials work with their counterparts in nations that export heavily to the United States to pre-screen cargo containers. In addition, America's busiest ports have been outfitted with scanners and sensors to provide a second layer of defense.

Even so, only a tiny fraction of the containers entering the United States, less than 10-percent, are actually examined. In a recent report, a federal watchdog agency, the Government Accountability Office, found that efforts to boost U.S. port security often have been badly conceived and poorly implemented, and have suffered from a lack of communication among agencies and inadequate funding.

As an example of a good idea gone awry, Ms. Wrightson pointed to an initiative to provide new, standardized identification cards to port employees to help prevent terrorist operatives from gaining access to the facilities. Other witnesses at the hearing testified that the backlog for these cards is in the hundreds of thousands, and that the current waiting period is well over a year.

The Coast Guard has estimated a $5-billion investment would be needed to fully overhaul U.S. port security. New Jersey Democratic Senator Frank Lautenberg complained that current funding levels stand at only $150 million a year. "It just isn't enough money to do the job. It is not. We do not recognize the significance [of the threat]. We do not recognize the risk," he said.

Any terrorist attack in which materials were traced back to a cargo container would result in the closure of U.S. seaports for an extended period of time. Aside from the human tragedy, financial losses under such a scenario would be measured in tens of billions of dollars.