The Obama administration has failed to meet a legal deadline for scanning all shipping containers for radioactive material before they reach the United States, a requirement aimed at strengthening maritime security and preventing terrorists from smuggling a nuclear device into any of the nation’s 300 sea and river ports.

Stephen Flynn, a terrorism expert at Northeastern University and a former Coast Guard commander who has studied container security, said, “The current system is woefully inadequate for stopping any determined adversary who wants to get a weapon of mass destruction into the United States.”