As one of a slew of goals seeking greater international cooperation on arms control, Barack Obama promised during the campaign to "lead a global effort to negotiate a verifiable treaty ending the production of fissile materials for weapons purposes."

Fissile materials -- mainly highly enriched uranium and plutonium isotopes -- are capable of sustaining the chemical reactions necessary to create a nuclear explosion. Banning the production of additional fissile materials wouldn't prevent states from developing additional weapons - each of the five "official" nuclear powers (the United States, Russia, France, the United Kingdom and China) still has large stockpiles, even if they have stopped producing fissile materials. The rogue nuclear nations of Pakistan, India, North Korea, Iran and possibly Israel all continue to produce bombmaking material, but their reserves are much smaller, making them unlikely candidates to join the treaty.

Still, such a treaty would make it more difficult for nations to join the nuclear club, particularly if it has the strong verification measures Obama seeks.

Obama has taken initial steps toward fulfilling the promise. In a speech in Prague this April, Obama called for a nuclear weapon-free world. And to get started on that goal, he said he'll push for what has generally been called the Fissile Material Cutoff Treaty.

"And to cut off the building blocks needed for a bomb, the United States will seek a new treaty that verifiably ends the production of fissile materials intended for use in state nuclear weapons. If we are serious about stopping the spread of these weapons, then we should put an end to the dedicated production of weapons-grade materials that create them. That's the first step," Obama said.

Some progress has been made. In 2009, the 65-nation Conference on Disarmament agreed for the first time in a decade on an agenda for disarmament, including the creation of a working group solely dedicated to discussing a ban on new weapon-making materials. But key nations -- including China, India, Pakistan and Israel -- have reservations about the treaty, and crafting a global agreement will be difficult.

Still, Obama has advanced the idea and he'll have opportunities to pursue it in 2010, with the White House hosting a Global Nuclear Security Summit in March and the 2010 Nuclear Non-Proliferation Treaty Review Conference beginning in New York this spring. For us, that's enough to rate this promise In The Works.