One of the key announcements at the Nuclear Security Summit today was that enough countries have ratified the amendment to the Convention on Physical Protection of Nuclear Materials (CPPNM) for it to enter into force. The 1980 CPPNM criminalizes nuclear theft and includes requirements for securing civilian nuclear material in international transport.  In 2005, a proposed amendment to the CPPNM was opened for signature that would extend its coverage to include physical protection for materials in domestic use, storage, and transport, and sabotage of nuclear facilities.

This is a long-awaited and significant step for strengthening the international nuclear security regime. Entry into force of the CPPNM will trigger a review conference where states can evaluate implementation of the convention after five years and, if parties choose to do so, review conferences at regular five-year intervals. This may serve as a useful tool to sustain international attention to nuclear security in lieu of the summit process. 

Although it has taken more than a decade for the amended convention to enter into force, there has been a flurry of activity in recent years. The majority of states that have ratified the amendment have done so during the nuclear security summit era. Most notably, the United States, which originally proposed the amendment, ratified it in 2015, after the implementing legislation for the amendment languished in Congress for years.

While this represents important progress, its significance should not be overstated. The convention is not perfect. Its requirements for securing civilian nuclear material are vague. The amendment does not include specific standards for physical protection. More work is needed to help create specific and binding requirements for nuclear security around the globe. 

Additionally, a key next step is to further universalize the CPPNM. There are still countries with nuclear facilities or nuclear weapons-usable materials that have not joined the convention, are not bound by its provisions, and should be pressed to accede now that the convention has entered into force. This would be an important next step for the United States to pursue.