This week, US President Barack Obama has been grabbing headlines with his efforts to revitalize the Strategic Arms Reduction Treaty — a US/Russian agreement to reduce the nuclear arsenals of both nations.

Such efforts will be applauded worldwide, but another decision by the Obama administration deserves equal acclaim. On 29 June, the president quietly cancelled a lengthy environmental review that was the first step in allowing the resumption of commercial nuclear reprocessing in the United States. Nuclear reprocessing chemically separates uranium and plutonium from spent nuclear fuel so that it can be reused in specialized reactors. The same technique can be used to purify material for nuclear weapons, and it is partly for that reason that the United States decided to halt reprocessing in the 1970s.

Obama's predecessor, George W. Bush, sought to reverse that decision. He thought that reprocessing could be part of a broader approach that would see used fuel from non-nuclear-weapons states brought to the United States for reprocessing. As part of the Global Nuclear Energy Partnership programme, Bush advocated the construction of a demonstration commercial reprocessing plant, and an environmental review was already under way when Obama came into office.

Such a plant, had the plans been allowed to continue, would have been both costly and counterproductive. Proliferation worries aside, reprocessing is complex, expensive and creates a liquefied stream of highly radioactive waste that is difficult to dispose of. The technology is likely to be needed within the next two decades, so Obama is right in his decision to allow research into ways to improve reprocessing, while constraining the programme to one of basic science.

The decision to halt commercial nuclear recycling sends a clear message that the United States is committed to nuclear non-proliferation. Such decisions, together with diplomacy such as that taking place in Russia, are deliberate and encouraging first steps towards building an international consensus on reducing the threat from nuclear weapons.