for-phone-onlyfor-tablet-portrait-upfor-tablet-landscape-upfor-desktop-upfor-wide-desktop-up

Q+A: Why is a U.S.-Russia nuclear deal important?

(Reuters) - Russia and the United States have reached agreement on a new nuclear arms reduction treaty, a Kremlin official who asked not to be identified said on Wednesday.

A White House spokesman said a deal on a successor to the 1991 Strategic Arms Reduction Treaty (START I) was very close but there were “still some things that need to be worked out.” He said Presidents Barack Obama and Dmitry Medvedev would likely speak soon.

“We are very close to having an agreement on a START treaty, but we won’t have one until President Obama and his counterpart Mr. Medvedev have a chance to speak,” White House spokesman Robert Gibbs said.

The two largest nuclear powers have been formally negotiating on a successor to the 1991 Strategic Arms Reduction Treaty (START I) since April 2009.

* WHAT IS THE NEW TREATY?

- Presidents Obama and Medvedev in April, 2009, said they wanted to agree a new deal by the December 5 expiry date of START I but talks snagged and the two sides agreed to act in the spirit of START until a replacement was ready.

The two leaders agreed in July that a new treaty would limit operationally deployed nuclear warheads to 1,500-1,675, with a more specific limit to be determined in talks, cutting from current levels of 2,200-2,700.

In the 2002 Strategic Offensive Reductions Treaty (SORT), also known as the Moscow Treaty, each side agreed to cut strategic nuclear warheads to 1,700-2,200 by 2012.

Obama and Medvedev said the limit for delivery systems -- jargon for the bombers, missiles and launch systems that deliver a warhead to a target -- should be in the 500-1,100 range.

* WHY IS A NEW DEAL IMPORTANT?

-- Washington and Moscow say finding a replacement for START I would help “reset” relations after a period of tension. Obama has said improving relations with Russia, a key player in Iran and a source of support on Afghanistan, is a priority.

-- START I played an important role in reducing the superpower brinkmanship of the Cold War.

-- Both the United States and Russia -- which hold 95 percent of the world’s nuclear arms -- are committed to reducing the number of atomic weapons.

Moscow and Washington realize their nuclear superiority is not threatened by any other power so, officials say, it makes sense to get rid of more weapons.

-- Russia’s vast store of Soviet-era nuclear weapons is one of the factors keeping Moscow at the top table of world politics.

After Russia’s conventional forces were starved of cash in the chaos that followed the fall of the Soviet Union in 1991, its still mighty nuclear deterrent is the centerpiece of the Kremlin’s military doctrine.

-- A new deal is expected to include detailed verification and procedures to ensure that cuts can be checked, though not as strict as those in START I. The 2002 Moscow Treaty did not contain them, cited by arms experts as a fundamental flaw.

The verification procedure is important because it allows the former Cold War foes accurately to predict how many weapons each side has and thus reduces the chance of a new arms race.

-- A replacement for START I is seen as the first step toward much deeper cuts. Both sides hope an agreement on START could lay the ground for more ambitious talks about reducing the silos of thousands of non-deployed nuclear warheads and shorter-range tactical nuclear warheads.

Those talks could also impose must bigger cuts to deployed strategic warheads and delivery systems.

-- A deep cut by the world’s two biggest nuclear powers could help create the momentum for a nuclear security summit Obama is hosting in mid-April and a May conference to review the 1970 nuclear Non-Proliferation Treaty.

* WHAT ARE THE PROBLEMS?

- The two sides have agreed on a news blackout from negotiations in Geneva, so there have been few details about what has caused the delay in achieving a deal.

- Russian Prime Minister Vladimir Putin said in December that U.S. plans for a missile defense system were the main obstacle to reaching a new deal, suggesting Moscow wanted it to limit missile defenses.

Obama and Medvedev agreed in July that the treaty will contain a provision describing the relationship between offensive and defensive weapons, but the United States says the pact is not the place for details on missile defense.

-- Working out how to count nuclear weapons seems simple at first glance, but can be exhaustingly difficult. For example, if a missile carries 10 warheads, should it be one weapon or 10? How does one count a missile that can carries 10 warheads, but has only one warhead currently deployed on it?

-- Russia wants to see the number of delivery systems to be further limited. However, Moscow has worries about such systems which have had their warheads removed but which could swiftly be deployed in the event of conflict.

-- Russia has also expressed concern that the United States could use ICBMs to carry conventional warheads.

-- Russia is concerned that the United States may simply increase the number of its new conventional weapons, some of which can be almost as destructive as nuclear bombs.

Writing by Guy Faulconbridge and Steve Gutterman in Moscow; Editing by Jon Hemming

for-phone-onlyfor-tablet-portrait-upfor-tablet-landscape-upfor-desktop-upfor-wide-desktop-up