The draft treaty is a mere 20 pages long. But it could just as well be 20,000.

A successor to the Cold War-era nuclear arms reduction treaty remains out of reach despite repeated assurances from U.S. and Russian officials about an imminent deal.

Muddying the waters, Russian officials from President Dmitry Medvedev on down have sent mixed signals about Moscow's readiness to sign.

Just this week, Foreign Minister Sergei Lavrov announced that the follow-on to the 1991 Strategic Arms Reduction Treaty would be signed in a matter of weeks — in late March or April.

But on the same day that he spoke, State Duma Speaker Boris Gryzlov warned that lawmakers would not ratify the treaty, "if it does not take into account the link between strategic offensive weapons and missile defense."

All eyes are on U.S. Secretary of State Hillary Clinton, who arrived in Moscow on Thursday for a two-day visit, to see whether she can make any headway on the issue. Clinton is expected to meet with Medvedev on Friday.

The stakes are sky-high. No one, of course, expects nuclear war if the pact is not concluded soon; the old START treaty, after all, expired in December.

But the moral authority of Washington and Moscow hangs in the balance. If the two leading nuclear powers do not reach a deal soon, they could find themselves in the awkward position of demanding nuclear disarmament from other countries at an international summit in May while being forced to acknowledge that they could not reduce their own arsenals.

"We are making very good progress. I can't predict to you exactly when the agreement will be completed but … we are getting closer," Undersecretary of State William Burns told reporters as Clinton flew to Moscow, Reuters reported.

UN Secretary-General Ban Ki-moon, who is also in Moscow, urged Medvedev to sign the treaty with Obama "as soon as possible."

Medvedev responded in English: "I hope so."

The Kremlin suggested last weekend that Medvedev was ready to set a date for the signing, releasing a statement after a phone call between Medvedev and Obama that said negotiations were going so well that it was now "possible to talk about concrete dates."

Negotiators entered their 10th round of talks in Geneva on March 9, and their attention is centered on the wording of a document that, according to Lavrov, covers a scant 20 pages. The final treaty, however, will be accompanied by “a far more voluminous document” of various protocols, Lavrov said Tuesday.

Medvedev and Obama agreed on the main component of the treaty — reducing their countries' nuclear arsenals to between 1,500 and 1,675 deployed warheads — at a Moscow summit in July.

Subsequent negotiations, however, bogged down over Russian demands to link offensive nuclear weapons and missile defense to prevent the United States from setting up elements of a missile shield in Europe.

At the July summit, Obama and Medvedev adopted a vaguely worded declaration that the treaty would have a clause acknowledging the interconnection between offensive and defensive nuclear weapons, but Michael McFaul, Obama’s Russia adviser, told journalists at the time that the United States would not view offensive weapons and missile defense as a single issue.

Some U.S. lawmakers have increased pressure on Obama in recent weeks not to bow to Russia's demands on the treaty, saying the United States needs the missile shield to ensure its security.

Complicating matters, the United States unveiled plans last month to deploy interceptor missiles in Romania, arguing that they are needed to prevent a potential missile strike from Iran.

Bulgaria also expressed willingness to host elements of a U.S. missile defense shield on its soil. The developments angered Russian officials, who have demanded explanations from the United States and both European countries.

“Obama’s declaration in July acknowledged the linkage … but then came the announcement of interceptors in Romania without any consultations with Russia, stealing the value of the previous American declarations,” said Vladimir Yevseyev, a nuclear security analyst with the Institute of Global Economy and International Relations.

Foreign Ministry spokesman Andrei Nesterenko reiterated the offensive-defensive weapons link Thursday, saying the "unrestrained deployment of missile defense systems by one state or military political bloc could undermine international nuclear disarmament efforts."

Russia has insisted on the link after former U.S. President George W. Bush's administration drew up plans to install elements of the missile shield in Poland and the Czech Republic — a project that had poisoned U.S.-Russian relations for several years. Russian military planners argued that such facilities — which Washington maintained were intended to neutralize a possible missile strike from Iran — would undercut Russia's ability to deliver a retaliatory nuclear strike against the United States if it decided to attack Russia first.

Obama ditched Bush's plans in September, paving the way for a "reset" in relations between the two countries.

Currently, nothing legally precludes the United States from deploying missile defense systems on the territory of its allies after it unilaterally withdrew from the 1972 Anti-Ballistic Missile Treaty in December 2001, much to the frustration of then-President Vladimir Putin.

Russia is concerned that the United States' technological superiority will one day allow it to develop missile interceptors capable of destroying Russian missiles from U.S. bases in Europe, even if the trajectory of the Russian missiles pass over the Arctic, said Yevseyev, the nuclear security analyst.

Meanwhile, the clock is fast ticking down on the 2010 Review Conference of the Parties to the Treaty on the Non-Proliferation of Nuclear Weapons, which will be held from May 3 to 28 at the United Nations. The conference, which convenes every five years, will be attended by the representatives of all 189 countries that have signed the 1986 treaty, the pillar of global nuclear disarmament and arms control.

If Russia and the United States do not sign their treaty by then, other countries, including those believed to be on the cusp of achieving military nuclear capabilities like Iran, will at best accuse them of hypocrisy, said Sergei Oznobishchev, an analyst at the Institute of Strategic Assessments.

"This would be a scandal. Then these countries would tell Washington and Moscow, 'You are supposed to be the beacons of nuclear disarmament, and you don't comply with NPT's demands for nuclear disarmament," he said.