The new administration has signaled its intent to swiftly engage Russia in negotiations on deeper cuts in their respective arsenals, with the ultimate aim of reducing them to zero.
But US Defense Secretary Robert Gates has been leading another kind of charge, arguing in the final months of the previous administration that deeper cuts must be underpinned by production of a new warhead to replace an ageing nuclear stockpile.
"To be blunt, there is absolutely no way we can maintain a credible deterrent and reduce the number of weapons in our stockpile without either resorting to testing our stockpile or pursuing a modernization program," he said in an October 28 speech.
Gates' speech at the Carnegie Endowment for Peace, says Jan Kristensen, an analyst at the Federation of American Scientists, was "an attempt to set a bottom line."
In Kristensen's view, the secretary's message was:
"You can cut the numbers, but below that we need to have a strong capability, not only to maintain what we have, but also to build up if we need to."
Kristensen added: "That is the big clash."
Gates is not alone in his thinking.
General Kevin Chilton, head of the US Strategic Command, warns that the United States is "living today off the largesse of an industrial base and a concept that was developed to support the Cold War which is many years in the rear view mirror right now."
A Pentagon advisory panel led by former defense secretary James Schlesinger warned this month of a weakening US deterrent.
On the other hand, former secretaries of state Henry Kissinger and George Shultz, former defense secretary William Perry and former Senator Sam Nunn say that nuclear weapons are increasingly ineffective as a deterrent.
They called for a "world free of nuclear weapons" in a Wall Street Journal op-ed piece two years ago.
The debate is likely to intensify over the next year as the new administration reviews the US nuclear posture.
A bipartisan commission appointed by Congress is expected to weigh in April, and the Pentagon will undertake its own review later this year.
The White House has already staked out its position, declaring on its website that "Obama and (Vice President Joe) Biden will set a goal of a world without nuclear weapons, and pursue it."
They will stop production of new nuclear weapons, seek agreement with Russia to take missiles off hair trigger alert, and seek "dramatic reductions" in their respective arsenals, it said.
But, it also said, "Obama and Biden will always maintain a strong deterrent as long as nuclear weapons exist."
Proponents of modernization argue that as weapons in the existing stockpile age, doubts about their safety and reliability will inevitably grow, thereby lessening their deterrent value.
They want Congress to fund the production of a new so-called "Reliable Replacement Warhead," which would incorporate safety features in its design to prevent accidental detonation or unauthorized use.
The Congress, however, has been skeptical of the need for the RRW. Studies have shown no decline in the safety or reliability of the existing arsenal, and programs currently exist to extend their shelf life.
Moreover, critics fear that the program will open the door to production of new types of nuclear weapons for military uses.
Those suspicions were fueled by a series of Bush administration proposals that suggested it was looking for ways to use nuclear weapons in a host of new scenarios.
The proposals included mini nukes, precision low yield nuclear weapons, a "robust nuclear earth penetrator" for deeply buried targets, and concepts for using nuclear weapons to destroy chemical or biological weapons.
So when the administration turned around and proposed the RRW to replace the weapons in the existing arsenal, Congress balked.
"There's lots of things that can be done to make real improvements to the existing stockpile, that should satisfy the concerns of those people who are genuinely concerned about safety and reliability," said Joseph Cirincione, president of the Ploughshares Fund, a non-profit that supports nuclear disarmament initiatives.
"Only those who are using this as an excuse to expand the nuclear arsenal won't be pleased," he said.
Geoff Morrell, the Pentagon press secretary, said Gates has not had a chance yet to discuss his ideas on nuclear issues with Obama.
"I think the secretary believes that, fundamentally, we have not done a good job of selling the importance of the Reliable Replacement Warhead," he said. "But these are discussions that he is going to have to have with his new boss."