When highly radioactive material that can be used in a “dirty bomb” is moved to or from a hospital in New York City, it is done in the dead of night on cordoned streets with high security.

In Mexico two weeks ago, a truck moving a large canister containing radioactive material was hijacked at a gas station — where it had been parked with no security. The cobalt-60 that was stolen from the vehicle and then extracted from its protective lead shield is so potent that it is considered a significant national security threat under U.S. guidelines.

There are now no international mandatory requirements for how to control these dangerous materials — including how they should be transported. The International Atomic Energy Agency (IAEA), the international nuclear watchdog, has only issued recommendations, in the form of a voluntary Code of Conduct.This disconnect between how nations manage extremely dangerous nuclear materials sought by terrorists creates significant security vulnerabilities. If a dirty bomb is exploded anywhere in the world, it would cross the nuclear terrorism threshold and open the door to further attacks.

An IAEA meeting of 88 nations recently assessed the effectiveness of the Code of Conduct at its 10-year anniversary.  The participants acknowledged that the non-binding status quo is inadequate.

The nations insisted, however, that formalizing the commitments would undermine the voluntary code. So they shelved indefinitely a proposal to make the code legally binding and requiring states adhere to its guidelines.