The ever-present nature of nuclear risks was brought into focus when North Korea fired a ballistic missile, defying UN sanctions, in the middle of a nuclear security summit hosted by US President Barack Obama last week. The erratic, nuclear-toting North Koreans are hard to rein in but it's within the powers of world leaders to better secure the tonnes of nuclear material at hundreds of facilities globally. In the wrong hands, all it takes is a little plutonium, about the size of an apple, to wreak grievous harm on many people. Detonating a radioactive "dirty bomb" is precisely what groups like Al-Qaeda and the Islamic State in Iraq and Syria (ISIS) are striving to do, Mr Obama said. Lending credence to this is evidence gathered of the interest of the terrorists behind the Paris and Brussels attacks who had videotaped a senior manager working at a Belgian nuclear facility.
Nuclear terrorism will remain a persistent nightmare not just because of the creeping influence of ISIS but also due to the multiplying risks if more nations see nuclear power generation as a viable alternative to fossil fuel. Technopreneur Bill Gates' TerraPower, for example, claims it can develop "a sustainable and economic nuclear energy technology using next-generation safe, affordable, clean and secure" means. China, which has signed an agreement with TerraPower "to bring the world's most advanced nuclear reactor to market before 2030", according to an expert, already has 32 nuclear power reactors in operation and plans to build about 400 new nuclear reactors by 2050. With a mercantilist China becoming more self-sufficient in reactor production and South Korea seeing export opportunities for its nuclear expertise, a stream of buyers might turn to them, like the United Arab Emirates.
Certainly, one can take some comfort in the progress the world has made over the years to enhance nuclear security. More countries are passing laws to implement the safety recommendations of the International Atomic Energy Agency, and there are global steps to bring into force the amended convention on the physical protection of nuclear material. The question is whether leadership to drive such efforts will be sustained after Mr Obama. He saw through the last of this series of summits which he had launched six years ago.
Though no policy breakthroughs emerged last week, the summit served the purpose of reinforcing safety concerns which might have receded after the 2011 Fukushima nuclear disaster. All it takes is a single lapse to produce events that could be "a humanitarian, political, economic, and environmental catastrophe with global ramifications for decades", as Mr Obama noted. That would indeed "change our world". The effects of China's toxic air pollution from coal-fired plants have been likened to a nuclear winter. But a major nuclear accident or act of terrorism would be much worse.