In signing a new arms treaty with Russia and hosting a major nuclear terrorism summit, President Obama has shown leadership on his pledge to move toward a world without nuclear weapons. But is anyone following? At home, Obama faces a polarized Congress and a public focused on other issues, such as the economy. Although many experts think the Senate will approve the new strategic-arms treaty with Russia, prospects are dim for ratifying another Obama priority: a global pact banning nuclear tests. Internationally, there is also a mixed picture. Obama has won kudos, and a Nobel Peace Prize, for a policy that many perceive as less belligerent than that of President George W. Bush. But George Perkovich, a prominent nuclear expert, noted in a recent report that nuclear powers such as Russia, China and France had not rallied behind the idea of moving toward global disarmament. 'The result is a talented president ready to lead a long-term campaign to remove the existential threats posed by nuclear weapons, but as yet lacking sufficient colleagues and followers to make it happen,' wrote Perkovich, who is at the Carnegie Endowment for International Peace. Obama's policy will face a critical test next month, when nearly 200 countries are to gather at the United Nations to review the nuclear Non-Proliferation Treaty (NPT), which is credited with keeping a lid on the spread of nuclear weapons for four decades. Obama wants to strengthen the pact, which is under severe strain because of Iran's and North Korea's nuclear programs. The NPT is a bargain that gives all signatories the right to nuclear power while barring them from getting a bomb; the original five nuclear powers could keep their weapons but were to take steps toward disarming. India, Pakistan and Israel, all nuclear weapons states, did not sign the treaty and North Korea quit it in 2003. But it will be difficult to get tougher penalties because the NPT conference operates by consensus. Iran, which is a signatory and maintains that its nuclear program is peaceful, could block changes. To critics, the forum often becomes a place where nuclear have-nots bash the nuclear haves, no matter what they do. 'In one sense, the United States will be perceived as genuinely having regained a position of leadership,' said Linton Brooks, a top nuclear official in the past two Republican administrations. 'Whether you'll be able to point to concrete results of that leadership, I simply don't know.' The Obama administration is especially eager to avoid a repeat of the failed 2005 conference, at which the Bush administration was accused of ignoring its own obligations to move toward disarmament. Obama will try to establish his credibility at the conference by pointing to his recent achievements: the U.S.-Russia Strategic Arms Reduction Treaty (START), and his new nuclear policy, which reduces the role of the weapons in U.S. defense strategy. Still, the administration could face trouble from policy contradictions inherited from its predecessors. U.S. presidents have been silent about Israel's nuclear program, which that country does not publicly acknowledge or deny. U.S. officials and analysts worry that the NPT conference could be dominated by a push by Arab states to demand a nuclear-free zone in the Middle East. Meanwhile, the United States, following up on a 2008 deal reached by the Bush administration, struck a deal last month allowing India to get power for its nuclear energy plants by extracting plutonium from spent U.S. nuclear fuel. But because India never signed the NPT, its facilities were not subject to international nuclear inspectors, who could detect whether the plutonium had been diverted to make a bomb. 'The chief problem with this agreement is that the U.S. is allowing a non-NPT member rights that we're not offering to NPT members,' said Daryl Kimball of the Arms Control Association, an independent group. Pakistan is so unhappy about the India deal that it recently blocked talks on another part of the Obama agenda: getting a treaty banning production of weapons-grade nuclear material. Pakistan's representative to those treaty talks, Zamir Akram, said his government's early optimism about the administration 'had been short-lived.' Administration officials acknowledge that it will not be easy to reach their goals, but they say they have reversed momentum at a moment when the Non- Proliferation Treaty was fraying. Obama has tried to emphasize U.S. support for the treaty in multiple ways: holding arms talks with Russia, promoting access to peaceful nuclear energy, and embracing a goal of eventual global disarmament. 'The fundamental theory of the agenda the president laid out last year is, it takes movement on a whole range of fronts at once to strengthen the NPT and the nonproliferation regime,' said Benjamin Rhodes, the White House director of strategic communications. -0-< Staff writer Steven Mufson contributed to this report. 