However, much more significant cuts in long-range nuclear weapons could take years of negotiation with the Russians, who do not share Obama’s ambitious disarmament vision. Nuclear weapons are, in fact, looming larger in Russia’s security equation at a time when their role in US strategic thinking is becoming more circumscribed,

One year after unveiling his vision here for a world without nuclear weapons, Obama returned this morning to sign a treaty with the Russian president that both sides call a major step forward on worldwide arms control.

The treaty is therefore a largely diplomatic rather than a pragmatic course of action for the moment. With US Congress having just passed through an exhaustive domestic agenda over health care reform, there are many other international items in queue before ratification and implementation of the new treaty will be felt.

It does, however stand the Obama Administration in good standing in terms of tackling the goals it has set for itself one by one – and the new treaty, the White House hopes, give Obama a stronger hand at next month’s review of the Nuclear Non-Proliferation Treaty (NPT)

For it’s part, the Russian Parliament – which will have to deal with new nuclear waste arising from the arsenal slashes – keeps putting off a second, crucial reading of a bill on dealing with radioactive waste in Russia, said Vladimir Slivyak, co-chair of the Russian environmental group Ecodefence on Thursday.

The bill on dealing with nuclear waste will be Russia’s first, and enormous elements of it are challenged by environmentalists and lawmakers alike. The ecological community likewise complains that it has been shut out of the discussions on the new radioactive waste bill.

The treaty signed today commits the former Cold War enemies to each reduce the number of deployed strategic warheads to 1,550  – 30 percent lower than the figure of 2,200 that each side was meant to reach by 2012 under the 2002 Strategic Offensive Reductions Treaty (Sort).

They are also allowed, in total, no more than 700 deployed intercontinental ballistic missiles, submarine-launched ballistic missiles, and heavy bombers equipped for nuclear arms.

The new limit on delivery systems is less than half the current ceiling of 1,600 – though each heavy bomber counts as one warhead irrespective of the fact that it might carry multiple bombs or missiles.

If ratified by lawmakers in both countries, the treaty will replace the Strategic Arms Reduction Treaty (Start) of 1991, which expired in December.

Pomp and circumstance in Prague

In a ceremony covered my world media at the medieval Prague Castle, Obama and Mevedev signed a “New START” treaty that administration officials say will bring U.S. and Russian nuclear arsenals to their lowest levels since the early 1960s.

The White House says the treaty will reduce the number of long-range deployed nuclear warheads by 30 percent, while also taking the two nations several strides forward in overall relations.

“One year ago this week,” Obama told reporters, “I came here to Prague and gave a speech outlining America’s comprehensive commitment to stopping the spread of nuclear weapons, and seeking the ultimate goal of a world without them. I said then – and I will repeat now –  that this is a long-term goal, one that may not even be reached in my lifetime.”

“But I believed then –  as I do now,” Obama continued “that the pursuit of that goal will move us further beyond the Cold War, strengthen the global non-proliferation regime, and make the United States, and the world, safer and more secure,” he said.

Medvedev, who sat by Obama’s side for the signing in an ornate hall of Prague Castle, said: “Here in this room a truly historic event took place … I believe that this signature … will create safer conditions for life here and throughout the world.

“Just a couple of months ago, (this) looked like mission impossible,” Medvedev added, but now, “this is a win-win situation. No one stands to lose from this agreement … The entire world community has won.”

Russians warn they can pull out

As Obama officials herald the new treaty as a sign of dramatic progress in US-Russian relations, Russian officials have been issuing warnings that they could pull out of the agreement at some future date. Foreign Affairs Minister Sergei Lavrov has publicly emphasized that Russian adherence to the treaty’s terms is linked to how the US acts on its missile defense program.

In a blog post on the White House website this morning, the White House’s new point man on the ratification effort, Brian McKeon downplayed the warnings, suggesting that they are less significant than the actual language of the hard-wrought treaty.

“Most treaties have a simple withdrawal clause, allowing a country to exit the particular treaty for any reason or no reason,” wrote McKeon, senior adviser to the National Security Council and Deputy National Security Adviser to Vice President Joe Biden. “The withdrawal clause in the New START Treaty has a higher bar; it gives a party the right to withdraw if it decides that “extraordinary events” related to the treaty have “jeopardized its supreme interests.”

The START agreement bodes well for cooperation between the U.S. and Russia on missile defences that have strained relations between the two in recent years, the leaders said. That relationship “had started to drift,” Obama said today. “Together, we have stopped the drift.”

Obama optimistic treaty has meaning

“I’m actually optimistic that having completed this treaty sends a signal around the world that the U.S. and Russia are prepared to take leadership (in) preventing the spread of nuclear weapons as well as materials,” Obama told reporters during a brief news conference after the signing.

“We have repeatedly said we would not do anything that limits my ability . . . to protect the American people … We also want to make clear that the approach we’ve taken is in no way intended to change the strategic balance between the U.S. and Russia,” he said.

“It matters to us what will happen to anti-missile defense,” Medvedev said. “We will watch how these processes develop… Ths is a flexible process, and we are interested in close cooperation … with our American partners.”

It was Moscow’s concerns over Washington’s plans to base interceptor missiles in Poland and a radar station in the Czech Republic that helped delay the new treaty. President Obama shelved the idea in September.

Despite his warning that Russia could pull out of the treaty, Lavrov told reporters that the New Start treaty marked a “new level of trust” between the countries.

He said the original Start treaty was “born from the Cold War” and contained much that was “discriminatory” towards Russia.

On Tuesday, President Obama unveiled the new Nuclear Posture Review, which narrows the circumstances in which the US would use nuclear weapons.

“The United States will not use or threaten to use nuclear weapons against non-nuclear weapons states that are party to the Non-Proliferation Treaty and in compliance with their nuclear non-proliferation obligations,” it said.