Q. What is the New START pact?

A. The 10-year treaty between the United States and Russia – formally the New Strategic Arms Reduction Treaty – is a successor to the first START nuclear arms-reduction pact signed in 1991. That expired last year.

 

Q. What does New START do?

 

A. Three main things: It would cap the number of deployed, long-range nuclear warheads on each side at 1,550, down from 2,200. It would reduce the number of deployed nuclear-carrying submarines, long-range missiles and heavy bombers to a maximum of 700, with 100 more in reserve (the U.S. currently has about 850 deployed; Russia has an estimated 565). Finally, it would re-establish a system in which each of the nuclear giants monitors the other’s arsenal. That system ended last year.

 

Q. Is it a dramatic step in disarmament?

A. Not really. Because there are different rules in START 1 and START 2 on counting warheads, the reduction may well be less than 30 percent. Also, the treaty doesn’t mandate that the warheads be destroyed — they will be added to the thousands the United States keeps in storage. But the treaty is a first step in President Barack Obama’s nuclear agenda, which envisions moving on to a second round of more ambitious negotiations. In addition, the Obama administration believes the treaty will bolster U.S. leadership in going after nuclear cheaters.

 

Q. What do opponents say?

 

A. They fall into different camps. Some believe traditional arms-control is outdated and it would be better to focus on building an ambitious missile shield, something like President Ronald Reagan’s “Star Wars” vision. Others accept the policy of recent presidents of a more limited shield to protect against threats from countries such as Iran and North Korea.

But they worry about a few mentions of missile defense in New START. While those phrases would not legally bar the United States from carrying out its current missile-defense plans, some Republicans worry Russia would seize on them to pressure Washington in the future.

Finally, some senators are angry about the process. Republicans have complained about considering the treaty in the waning days of a lame-duck session in which Obama has racked up several legislative victories. Republican leaders had wanted the vote postponed until next year, when they will have more clout thanks to victories in the midterm elections.