For the White House and the gang of four, the basic steps needed to reduce the threat of possible nuclear catastrophe include:
•Reducing current nuclear stockpiles;
•Locking down known fissile material and attendant technology;
•Convincing other nations not to move outside the nonproliferation regime, the central international treaty of the cold war, now widely described as "fraying" or worse.
Those steps have more than rhetorical urgency. In April and May, the White House takes up all three issues in what US officials describe as an effort to create needed momentum and overcome substantial inertia and doubt.
The new START treaty, which was scheduled to be signed by Obama and Russian President Dmitry Medvedev in Prague on April 8, reduces strategic nuclear warheads by about 40 percent, from 2,700 to 1,550 on each side, and halves the number of launchers. (In the 1980s, the two sides had roughly 20,000 warheads.) It will then need to be ratified by two-thirds of the US Senate.
Trying to build on the START momentum, the White House hopes to forge an agreement to contain plutonium and uranium at the April 12 fissile materials summit in Washington.
"We need to get lots of countries to adopt very strong physical protection measures," says a senior US official. "This would secure and lock down all materials in four years. It is a big ask for us in [dealing with nuclear] smuggling and screening cargo ships. We get the buy-in if we do our part."
Part of the fissile material safeguards discussion may involve a global nuclear fuel bank. It would loan states that want to generate nuclear power the uranium they need to fuel civilian reactors – eliminating the enrichment process that allows them to create weapons-grade material.