VIENNA ― World leaders have devoted increasing attention in recent years to the risk of terrorists obtaining nuclear or other radioactive material. That’s the good news. But all of us need to act with greater urgency in translating good intentions into concrete action.

The risk of nuclear or other radioactive material falling into the wrong hands is all too real. There have been embarrassing security lapses at nuclear facilities, and sensitive material is often inadequately secured. Indeed, the International Atomic Energy Agency records numerous cases of theft and other unauthorized activities involving nuclear and radioactive material every year. Most of these incidents are fairly minor, but some are more serious. Some material goes missing and is never found.

An incident in Moldova two years ago involving highly enriched uranium ― which can be used in a nuclear weapon ― illustrates both the scale of the threat and the possibility of effective countermeasures if countries take the problem seriously. Police seized a quantity of the substance from an individual who was attempting to sell it. The smugglers had tried to evade detection by building a shielded container ― a worrisome level of sophistication on their part.

Fortunately, the Moldovan authorities had been working hard to improve their detection capabilities. They had also shared information with their counterparts in other countries. The uranium was seized in a sting operation. Arrests were made and several people received prison sentences.

Most cases of attempted trafficking do not involve nuclear material; rather, they involve radioactive substances of the type held in hospitals, factories, and other locations all over the world. These locations are generally not as well protected as nuclear facilities. Even a relatively small amount of material such as cobalt-60 ― used in radiotherapy ― could cause serious harm if combined with conventional explosives in a so-called dirty bomb (or otherwise deliberately used to expose the public to dangerous radiation).

Foreign and energy ministers will have an opportunity to strengthen the global nuclear security framework when they meet at the International Conference on Nuclear Security: Enhancing Global Efforts in Vienna on July 1-5. This will be the first such event that is open to all countries.

At the top of the agenda should be ratification of improvements to a crucial nuclear security instrument ― the Convention on the Physical Protection of Nuclear Material. The proposed amendment would oblige countries to protect nuclear material when it is being used or stored, not just when it is being transported internationally, as is the case now. It would also require countries to protect nuclear facilities against acts of sabotage, which could have consequences similar to those of nuclear accidents.

The proposed amendment was agreed in 2005, but it still has not entered into force, because not enough countries have ratified it. That needs to change if major vulnerabilities are to be addressed successfully.

Nuclear security is a matter of global concern, and global action is required. Efforts by just a handful of major players will not be sufficient to keep the world safe. We cannot afford to have weak links in our chain of defense. All countries must play their part.

Even countries that do not possess nuclear or other radioactive material need to act. There is evidence that criminal and terrorist gangs have attempted to traffic material through countries perceived to have lax security. It is imperative that they do not succeed.

One simple measure would make a big difference: All countries should allow peer reviews of their nuclear-security arrangements by international experts. Peer reviews have been shown to work ― for example, in improving safety at nuclear power plants. Everyone benefits. Bringing experts in nuclear security together to share their experience is a no-brainer. More countries need to do it.

Following Moldova’s example, all countries should also ensure that law-enforcement officers are properly trained to respond to the menace of nuclear terrorism. Countries must invest in equipment and infrastructure and share information across borders.

The fact that there has been no major nuclear terrorist attack should not lull us into a fall sense of security. The threat remains. We must seize the opportunity to ensure that our worst nightmare never becomes our waking reality.

By Yukiya Amano

Yukiya Amano is the director-general of the International Atomic Energy Agency. ― Ed.

(Project Syndicate)