In a debate that could affect the future of global security, a movement is growing to rethink some of the most basic principles guiding US arms control.
For nearly half a century, nonproliferation efforts have focused on bilateral arms reductions and the principle of "mutually assured destruction" - that in the event of a final atomic confrontation, each side would be destroyed.
Those tenets, however, are being nudged aside by a general desire to look for new answers in a world that has changed dramatically since the Soviet Union broke up and the cold war ended. Anchoring the movement is a steady tip in the scales of arms-control thinking away from offensive weapons and toward defensive weapons, such as national missile defense, a shield against incoming attacks that is under consideration for deployment.
"We have a number of years to go in this direction," says retired Maj. Gen. William Burns, a former director of the US Arms Control and Disarmament Agency. "But I think it's inevitable."
The shifting emphasis was evident in a "statement of principles" agreed to Sunday by Russian President Vladimir Putin and President Clinton on missile defense. While the two sides remain far apart on the issue, Moscow formally acknowledged that ballistic missile threats posed by "rogue" nations need to be addressed.
As further evidence of a shift, the Russian leader suggested over the weekend that Washington and Moscow collaborate on new ways to shoot down enemy missiles.
The Russian plan, however, is intended to be a substitute for the nationwide defense shield under consideration by the Clinton administration to protect the United States from incoming warheads. Instead, Moscow envisions a more limited, ground-based system to protect against the nuclear threat posed by "rogue" states.
In the US, the debate over shifting to a more defense-oriented strategy has crossed partisan lines and has spurred at least two authoritative arms-control groups into beginning new studies on the topic.
It was brought to life by the Republican presidential hopeful, Gov. George W. Bush of Texas, who has put forth a not-yet-detailed proposal for the US to unilaterally slash the number of offensive nuclear weapons, while at the same time building an extensive defense system - at home and abroad - to guard against missile attack.
He and his advisers argue that the US is still handling arms control in the context of the cold war, when the Soviet Union and the US amassed huge arsenals of deterrent nuclear weapons. He argues that the US should, however, begin paying more strategic attention to potential attacks from so-called rogue states like North Korea and Iran, which could be capable of a long-range attack in as few as five years.
"When it comes to nuclear weapons, the world has changed faster than US policy," Mr. Bush said in a recent press conference.
Bush's plan - both tantalizing and ambitious - has usurped the Clinton administration, and Mr. Gore, who has yet to articulate a direct response. It has also surprised some of his fellow Republicans, who do not necessarily favor unilateral arms reductions.
"It really exposes the weakness of the Clinton administration, which is arms control," says Joseph Cirincione, of the Carnegie Endowment for International Peace in Washington. "They haven't delivered very …