A NEW START: U.S. Secretary of State Hillary Clinton (second left) and Russian Foreign Minister Sergey Lavrov (second right) hold talks on issues including a new nuclear strategic arms reduction treaty in Moscow on October 13, 2009 (JIN BO)

After prolonged negotiations, the United States and Russia finally agreed on a successor accord to the Strategic Arms Reduction Treaty (START) in late March. The new treaty is slated to be signed on April 8 in Prague. Under the agreement, the two powers will each cut their deployed nuclear warheads to no more than 1,550, while bringing down the number of deployed delivery vehicles on each side to no more than 700.

Many experts believe this signals not just a victory for nuclear disarmament, but also a landmark in the annals of U.S.-Russia diplomatic relations. The resolution of the impasse toward the goal of a nuclear-free planet, moreover, will also serve U.S. President Barack Obama and his Russian counterpart Dmitry Medvedev well before their domestic and international audiences.

UN Secretary General Ban Ki-moon was quick to weigh in, saying the new treaty would give "significant impetus" to this May's review conference of the UN-backed Nuclear Non-Proliferation Treaty.

Tough negotiations

START, signed between the United States and the Soviet Union in July 1991, obligated each side to reduce its deployed warheads to no more than 6,000 and delivery vehicles to no more than 1,600.

After START expired in December 2009, Washington and Moscow failed to come up with a new treaty on a proper schedule. Eventually, however, the two sides gained enough ground to move ahead with their negotiations. Up until the end of the process, both sides cited "technical" differences as reasons behind the delay.

What are these "technical" differences?

Notably, there have been disputes over the exact number of missiles each side was prepared to surrender. As part of the accord, there have been two numbers—the nuclear warheads deployed, and the vehicles capable of delivering them.

In July 2009, the two sides agreed to limit the number of deployed warheads on each side to 1,500-1,675 on 500-1,000 delivery vehicles. Obama, however, wanted to further reduce the number of warheads to 1,000, so that the new treaty would have unprecedented significance.

Differences also existed regarding the numbers of delivery vehicles. Currently, Russia has about 620 delivery vehicles and 2,787 nuclear warheads. The United States, meanwhile, has 1,176 delivery vehicles for fewer than 2,200 warheads.

During negotiations, Russia expressed its expectation that the United States cut the number of its delivery vehicles, while the United States sought to maintain more delivery vehicles and fewer deployed warheads.

Further differences lay within verification and transparency. Russia tended to simplify verification procedures, while working to decrease outside monitoring and intervention. The United States, on the other hand, always hoped to maintain its monitoring arrangements at the missile assembly plant in Votkinsk, where Russia's modernized Topol and Bulava missiles are assembled.

Russia had operated a monitoring station at a missile assembly plant in Utah. But in 2001, it withdrew its monitoring team as the United States had ceased developing new missiles there.

In the negotiations, Russia insisted that, as the two countries are no longer enemies, such monitoring measures are obsolete. The Russians added that it was thus unfair for the United States to unilaterally maintain its monitoring team in the Votkinsk missile assembly plant. After some hard bargaining, the United States withdrew its monitoring team from Russia in December last year.

The two sides also differed on the subject of vehicle modification. The United States planned to equip nuclear delivery vehicles, which were to be reduced in number by the new treaty, with conventional warheads.

Washington then insisted the new treaty not set limits on what it characterized as conventional delivery vehicles. Russia, however, argued that, as these delivery vehicles were deemed to have nuclear capacity, they should be included in the overall limits on delivery vehicles.

The Bush administration strongly pushed for moves to load conventional warheads onto delivery vehicles, while the U.S. military planned to attain this capacity by 2015. Moreover, the Pentagon announced its intention to invest $500 million in carrying out experiments on modifying strategic missiles for conventional weapons use on March 15.

But the two sides eventually reached a compromise by allowing Russia to own relatively more delivery vehicles on the condition that Moscow agrees not to include conventional delivery vehicles within the limits of the new treaty.

The multi-billion-dollar missile defense program—a cornerstone of the Bush administration's foreign policy earlier in the decade—was yet another obstacle for the signing of the new treaty.

Indeed, the placement of anti-missile systems and interceptors in Eastern Europe had long caused a strong rift in U.S.-Russia relations. Russia always believed the U.S. program created a lopsided balance of power between the two nations.

Washington has long contended that the placement of the anti-missile systems in Europe was needed to counter missile threats from Iran. Many analysts, as well as Russian officials, however, viewed these deployments as an aggressive effort to contain Russia militarily.