The world's two major nuclear weapons states are preparing to stage a public spectacle not seen since the peak of the cold war: full scale negotiations for a new deal to slash their still-bloated arsenals of offensive strategic arms.

President Barack Obama's administration has set Moscow's security community abuzz by signaling Washington's willingness to work up a replacement for the 1991 Strategic Arms Reduction Treaty, or START, which would otherwise expire at the end of this year.

Mr. Obama and Russian President Dmitry Medvedev are expected to set the ball rolling when they meet on the sidelines of April's G-20 meeting in London. Secretary of State Hillary Clinton will also meet Friday in Geneva with Foreign Minister Sergei Lavrov. Secretary Clinton offered a preview of the meeting during a gathering of NATO foreign ministers in Brussels. Regarding Russia, "It's time for a fresh start," Clinton said.

The high-level meetings ahead between the US and Russia are likely to be followed by intense activity as the two sides strive to map out a fresh accord by the Dec. 5 deadline.

Often described as the most effective arms control accord in history, START led to the removal of more than two-thirds of all strategic weapons and limited each side to the then-radical ceiling of 6,000 warheads deployed on no more than 1,600 delivery systems.

Moscow welcomes Obama's goal

But experts warn that the global security environment has shifted dangerously in two decades, and the old bipolar superpower standoff has been deeply complicated by the emergence of new nuclear wild cards, such as India, Pakistan, and North Korea.

They also worry that the old arms control framework may have been fatally damaged by the Bush administration's unilateral withdrawal from the 1972 Anti-Ballistic Missile Treaty, which banned defensive strategic weapons, followed by a decision to station anti-missile interceptors in Poland. Despite such concerns, official Moscow appears enthusiastic.

"Nuclear arms control is the one, single area where Russians feel like complete equals when they face their American counterparts across a table," says Fyodor Lukyanov, editor of Russia in Global Affairs, a leading foreign policy journal. "When we start serious talks [on START], it will say to us that Russia is finally back as a serious player."

Russian experts say they are excited by the signs coming out of Washington. According to a statement published on the White House website, Mr. Obama wants to move toward "a world without nuclear weapons" and is ready to partner with Moscow to seek "dramatic reductions in US and Russian stockpiles," of nuclear arms. A recent story in The Times of London quoted a White House official saying the US might seek to slash strategic arsenals down to 1,000 weapons on each side – an 80 percent reduction.

"We have heard these declarations from Obama," says Andrei Klimov, deputy chair of the Russian State Duma's international affairs committee. "This is very welcome. We are in favor of deep strategic cuts, but there is a complex knot of problems to be resolved. The balance needs to be maintained."

The Russians complain that Washington lost interest in serious arms control with Moscow after the USSR collapsed. But Russia and the US, between them, hold about 93 percent of the world's remaining 25,000 nuclear weapons, according to the Washington-based Center for Defense Information (CDI), and little has changed in the equation since the cold war's end.

Experts say that any serious attempt to engage other up-and-coming nuclear powers in arms control – much less convince countries like Iran and North Korea to dismantle their atomic programs – will require decisive moves toward disarmament by the big powers. Currently, according to CDI, China has about 410 warheads, France 384, Israel and Britain around 200 each, India about 60, and Pakistan 25.

"If Russia and the US are interested in keeping the nuclear non-proliferation regime alive, they must do their best to get a new framework for arms control going," says Anton Khlopkov, executive director of the PIR Center, an independent Moscow-based security think tank. "Otherwise, many other countries will see it as more hypocrisy from the big powers who, just as in the past, call on others to disarm but do not keep their own pledges."

Tight deadline approaches

The Bush administration responded to Russian pleas by signing the Strategic Offensive Reduction Treaty (SORT) with then-Russian President Vladimir Putin in 2002, which called for both sides to slash their arsenals to a maximum of 2,200 weapons on each side by 2012. But it's a deal the Russians say they'd prefer to forget, because it contained no provisions for verifying compliance and seemed, to them, a way for Mr. Bush to avoid discussing arms control with Moscow.

"This so-called SORT was a page-and-a-half long, and was basically a statement of intention with no follow up mechanisms at all," says Mr. Khlopkov. "Russia was, and is, interested in old-fashioned arms control talks with a full framework of mutual obligations."

The Russians claim that the Bush administration's opposition to structured negotiations led it to ignore all opportunities for prolonging START, thus leaving Obama with a very tight deadline to find a replacement for the accord. As soon as they start discussing fresh cuts in offensive strategic weapons, experts say, the US and Russia will run up against another Bush legacy: the lack of controls on antimissile systems.

"Back in the 1970s, the American approach was that development of defensive weapons must be blocked first of all, and that led to the ABM Treaty," says Yevgeny Bazhanov, vice rector of the official Diplomatic Academy in Moscow, which trains Russian diplomats. But the US broke out of the ABM Treaty in 2001, and began developing a global antimissile shield that includes plans to station interceptors in Poland, right near Russia's borders.

"I don't see how we can discuss strategic arms control in isolation from this larger context; the missile defense issue will have to be addressed as well," says Mr. Bazhanov. "But Russia is ready, and the signals all say Obama is ready too. It's a historic moment."