When a Superman-shaped drone crashed into a French nuclear plant on July 3 officials were lucky it was just Greenpeace demonstrating vulnerabilities at the facility, and not a terrorist group intent on attacking the site.

A hot mic shouldn't overshadow a dirty bomb. The Nuclear Security Summit in Seoul ended recently with two dominant story lines: President Obama's "hot mic" comments to Russian President Medvedev and the 53 participating governments congratulating themselves on the summit's outcomes. Both miss the key strategic problem that the Seoul Summit did not address: the need to unify the current patchwork, largely voluntary approach to nuclear security that is not commensurate with the risk or consequences of nuclear terrorism.

  Announcing a new free online course from The William J. Perry Project: The Threat of Nuclear Terrorism. In this custom-designed MOOC, former Secretary of Defense William Perry brings together internationally-renowned experts, scientists, political activists and scholars to address the critical, and often poorly understood, dangers of nuclear terrorism. This new course launches October 17th—you … Continued

Nuclear terrorism is the ultimate preventable catastrophe. If highly enriched uranium and plutonium are adequately secured or eliminated, they cannot be stolen for use in a nuclear device. In 2011, Director of National Intelligence James Clapper noted that "poorly secured stocks of [chemical, biological, radiological, and nuclear materials] provide potential source material for terror attacks." Osama bin Laden may be dead, but the threat of nuclear terrorism remains.

The prevention of nuclear terrorism, one of the foremost international security threats that we face today, relies on separate national regulations with little oversight. There are few international checks and balances on the physical protection of the treacherous material, which could be used to create nuclear devices by terrorists, aside from bilateral agreements and individual treaties formed at the will of individual states. This lack of binding guidelines and international oversight of nuclear security is inadequate for today's nuclear risks.

It is a fact that nuclear terrorism is a global threat and has become a worldwide concern. But what is particularly frightening is that there is no clearly defined plan for securing all nuclear materials. According to the Nuclear Threat Initiative's (NTI) Nuclear Material Security Index, there is no global consensus about what steps matter most in achieving nuclear security.

Highlighting the danger posed by nuclear terrorism and the need for an effective response, President Barack Obama came to office promising to "secure all vulnerable nuclear materials around the world within four years." The necessity of this goal is unquestioned. In fact, since 2004, at least four published official government reports have criticized the adequacy of the U.S. government's response to the threat of nuclear terrorism. The ability to achieve this objective, however, has been questioned.

Four years ago, President Barack Obama called preventing nuclear terrorism a top security priority. But even though he said in his State of the Union speech last week that Washington "would continue leading the global effort to secure nuclear materials that could fall into the wrong hands," the United States is only marginally safer from that threat today than it was at the beginning of his first term.

Bottom-up, business-led improvements will help keep the world safe from nuclear terrorism.

For years, American politicians on both sides of the aisle have agreed that nuclear terrorism is one of the most serious national security threats the United States faces. In 2013, President Obama must capitalize on this rare consensus point and on his own power as a second-term president. After all, despite ongoing polarization in Washington, bipartisan cooperation has been the norm for nuclear security since the launch of the Nunn-Lugar program more than two decades ago, making the issue a unique outlier in Washington -- and for good reason.

Almost no country in the world would refuse an invitation to join a collective declaration acknowledging nuclear terrorism as one of the most challenging threats to global security. However, defining a common view about how to advance practical measures that will prevent nuclear terrorism is not so easy. When it comes to nuclear security, it has always been difficult to go from statements to actions.

In the past six months, President Barack Obama has taken three major steps to protect the world from nuclear terrorism and advance the disarmament agenda. First, during his April speech in Prague, he outlined his arms control and nonproliferation objectives and announced a U.S.-led international effort to secure all of the world's vulnerable nuclear materials within four years.

Steps Washington and Moscow took to transform their space rivalry into cooperation can serve as a model for working together to help prevent nuclear terrorism.

Iran’s Natanz underground uranium enrichment site—a key nuclear facility for the country—went dark on Sunday in what Iranian officials called an act of “nuclear terrorism” carried out by Israel, bringing a shadow conflict between Iran and Israel into sharper focus and threatening to derail renewed efforts by Iran and the United States to revive talks on the Iran nuclear deal.

The Nuclear Security Summit taking place in Seoul next month is expected to reinforce the commitment of the international community to confronting the threat of nuclear terrorism. The summit process provides a unique opportunity to ensure that nuclear security receives the high-level attention it deserves from governments around the world. It also entrusts the participants with a special responsibility not to let this opportunity pass by.

As South Korea prepares for the second Nuclear Security Summit, scheduled to take place in Seoul next March, the momentum for collective international action on nuclear terrorism must be sustained. In the months before the 2012 talks, states will have to work together to retain focus on the summit's ultimate goal -- securing vulnerable nuclear material worldwide -- or else risk taking a step backward in the fight against the menace of nuclear terrorism.

While Washington, DC, is paralyzed by partisanship on most topics, there is one issue that commands overwhelming bipartisan agreement: the threat posed to US national security by nuclear terrorism.

In April 2010, representatives from 47 countries and three international organizations gathered in Washington, DC, for the first Nuclear Security Summit, an international effort created to strengthen fissile material security measures and prevent nuclear terrorism. Leaders endorsed the summit's objective of securing all vulnerable nuclear materials around the world in four years and signed consensus communiqué and work plan documents focused on compliance with today's nuclear material security regime.

The long-awaited report of the third Nuclear Posture Review is now scheduled for delivery to Congress on March 1. According to a recent New York Times article, the posture review will consider the prevention of nuclear proliferation and nuclear terrorism to be equally as important as the nuclear deterrence mission.

The 2010 Nuclear Security Summit in Washington, DC, was a milestone for nuclear security. Political leaders from 47 countries, including the United States, and multilateral organizations gathered to make a concerted global effort to protect vulnerable nuclear material and to prevent nuclear terrorism. Chinese President Hu Jintao -- putting aside China-US disputes over arms sales to Taiwan and the Dalai Lama's visit to Washington -- attended the summit, speaking positively of China's responsible and cooperative attitude toward international security.