The US Navy is shadowing a North Korean freighter that may be transporting military cargo banned by UN Resolution 1874. US defense officials have not identified the suspected military contraband, which could run the gamut from conventional weapons to missiles or even nuclear technology or components. The UN resolution imposed such tightly constrained means for enforcement that it now hinders international efforts to prevent North Korean nuclear and missile proliferation.

The UN resolution, passed on June 12 in response to North Korea’s recent nuclear test, is plagued with loopholes. The document merely “calls upon” rather than requires member nations to inspect cargo suspected of containing restricted materials. Nations can only inspect suspect vessels with the consent of the flag nation; without such consent, the ship must be directed to an “appropriate and convenient” port for the required inspection. China resisted efforts to base implementation on Article 42 of Chapter 7 of the UN Charter, which would have allowed military force to uphold the resolution.

The danger of North Korean proliferation is high, since it previously sold missiles to several countries and was assisting Syria to construct a nuclear reactor prior to it being bombed by Israel in September 2007. Media reports have cited the Kang Nam as a “known proliferator.” However, previous instances of law enforcement seizure of the ships (several North Korean freighters share the same name) were in response to safety violations rather than illegal cargo. A rumored October 2006 interception for suspected arms smuggling proved to be erroneous.

If the North Korean ship is carrying proscribed cargo, it would be the latest blatant act of defiance by Pyongyang against the international community and another test of the Obama administration. The North Korean ship has declared for Singapore where it would likely be subject to search by local authorities. But, if the ship deviates from its declared destination, Admiral Michael Mullen, the chairman of the U.S. Joint Chiefs of Staff, has said the US navy would not board the ship without permission since the resolution “does not include an option for opposed-boarding or noncompliant boarding.”

The numerous shortfalls of the UN resolution, and the dangers it poses for preventing North Korean proliferation, show the need for the Obama administration to continue to press the UN for more expansive rules of engagement to enforce the resolution. Because China and Russia will continue to be obstructionist, the Obama administration should also initiate a parallel multilateral effort to impose punitive measures on North Korean proliferation and illegal activities. Finally, the US should engage with other nations to define the circumstances in which North Korean ships would be boarded if they are suspected of carrying missiles or nuclear material.