The Obama administration seems ready to resuscitate relations with Russia, including by renewing nuclear-arms-reduction talks. Even before the inaugural parade wound down, the White House Web site offered up a list of ambitious nuclear policy goals, with everything from making bomb-making materials more secure to the eventual abolition of nuclear weapons.

That's welcome news, but for such goals to be realized, the White House will need to be prepared to reimagine and reshape the nuclear era and, against strong opposition, break free from cold war thinking and better address the threats America faces today.

George W. Bush actually started down this road. He reached an agreement with the Kremlin in 2002 to cut the number of operational strategic warheads on each side to between 1,700 and 2,200 by the year 2012, a two-thirds reduction. Washington is likely to reach that goal ahead of schedule. President Bush's efforts were propelled by the Nuclear Posture Review - a periodic reassessment of nuclear forces and policies - in December 2001. While still grounded in the belief that nuclear weapons are the silver bullets of American defense, the review let a little daylight into the nuclear bunker by acknowledging that nuclear-weapons policy had to be readjusted to deal with rapidly changing threats. Soon, however, the president's initiatives were overshadowed by the wars in Afghanistan and Iraq, his administration's absorption with the threat of terrorism and the gradual breakdown in relations with Russia.

President Bush's agreement with Moscow, which was built upon weapons reductions made by Presidents Bill Clinton and George H. W. Bush, is President Obama's starting point. But rather than settle for the next level - 1,000 active weapons seems to be the likely goal - the White House should reconsider the entire superstructure of nuclear-weapons strategy. This won't be easy. The mandarins of the nuclear establishment remain enthralled by elaborate deterrence theories premised on the notion that the ultimate defense against a variety of military threats is a bristling nuclear arsenal.

It's true that America's nuclear weapons still offer the hope of deterring attacks from countries like North Korea and, if it soon goes nuclear, Iran. But it is hard to imagine how they would dissuade a band of elusive, stateless terrorists from making a nuclear bomb and detonating it in New York, Washington or Los Angeles.

One provocative road map for moving away from nuclear deterrence comes from a quartet of cold war leaders - Henry Kissinger and George Shultz, former secretaries of state; William Perry, a former secretary of defense; and Sam Nunn, a former chairman of the Senate Armed Services Committee. Two years ago, they bridged their ideological differences to call, improbably, for the abolition of nuclear weapons, and they proposed a series of interim steps to reduce nuclear dangers, stop the spread of bomb-making materials and lay the groundwork for a nuclear-free world.

Even the quartet recognizes that "getting to zero" will be exceedingly difficult. But the issue today isn't whether the elimination of nuclear weapons is feasible. That's a distant goal.

An achievable immediate goal should be to cut the United States' and Russia's nuclear stockpiles down to the bare minimum of operational warheads needed to backstop conventional forces. As long as these two countries have far and away the most nuclear weapons, Washington looks hypocritical when it lectures other nations about the size of their arsenals or their efforts to develop nuclear weapons.

There's reasonable disagreement among experts about the minimum number of nuclear weapons the United States and Russia should maintain. The more emphasis you put on nuclear deterrence, the more potent you think the arsenal should be. And the more you want to engage the world in arms reduction and prevent proliferation, the more you consider radical cuts. To bring the number down below 1,000 would require determined presidential leadership.

The president's determination will be measured by how effectively he makes the case for Senate ratification of the 1996 Comprehensive Nuclear Test Ban Treaty. Leading scientists say that technological advances over the past decade have erased doubts about whether an international monitoring system can detect and locate underground tests outlawed by the treaty. The scientists also say that the United States has the technical expertise and tools to maintain the effectiveness of its nuclear weapons without underground testing, as has been successfully demonstrated since the United States stopped testing in 1992.

Ratification of the test-ban treaty would help build momentum for a 2010 review of the Nuclear Nonproliferation Treaty, the increasingly frail 1968 accord aimed at limiting the spread of nuclear weapons and eventually eliminating them. American leadership is essential to reinvigorating the treaty and buttressing nonproliferation efforts. The best way to avoid nuclear terrorism is to prevent terrorists from acquiring the highly enriched uranium needed to make the simplest nuclear bomb.

Listening to the discussion at a recent nuclear-weapons conference in Washington, I felt as though I had slipped back in time to the cold war and its arcane, often surreal debates about waging nuclear war and the doctrine of mutual assured destruction. It's heartening to see President Obama and his national-security team promising to elevate nuclear-weapons policy and free it from the shibboleths of cold war nuclear theology. Now they must put their words into action.