A sharply divided Senate Armed Services Committee voted on Friday to repeal a 10-year-old ban on the development of small nuclear weapons, asserting that the US must look at new ways of deterring terrorist groups and rogue nuclear powers like North Korea.
The administration of President George W. Bush, which requested the repeal, said it has no plans to develop a new low-yield nuclear weapon. But it contends that the existing prohibition has had a chilling effect on weapons research at a time when the US is trying to reconfigure its military to address post-Soviet threats.
The measure goes before the full Senate in two weeks, where opponents, mainly Democrats, have vowed to fight it. The House Armed Services Committee is scheduled to take up the proposal on Tuesday.
"We have tried for 50-plus years to make these weapons unthinkable," said Democratic Senator Jack Reed, "And now we're talking about giving them a tactical application. It's a dangerous departure."
Proponents, mainly Republicans, argue that low-yield warheads could be used to incinerate either chemical or biological weapons installations without scattering deadly agents into the atmosphere.
"Without committing to deployment, research on low-yield nuclear weapons is a prudent step to safeguard America from emerging threats and enemies who go deeper and deeper underground," said Republican Senator John Warner, who is chairman of the Armed Services Committee.
But senior administration officials have also argued that new nuclear weapons may be needed to deter emerging nuclear powers like North Korea and Iran. They contend that large warheads may have lost their deterrent value for the paradoxical reason that they are so destructive that world leaders no longer believe the US would use them against small countries.
Low-yield weapons might prove more effective in containing smaller nuclear powers precisely because they are less devastating and therefore theoretically more usable, the officials argue.
"We need to make sure our weapons will in fact be seen by other counties as a deterrent," Linton Brooks, the acting administrator for the National Nuclear Security Administration, said in an interview. "One element of that is usability. If nobody believes there is any circumstance where you will use the weapon, it is not a deterrent."
Arms control advocates and many Democrats contend that improvements in laser and satellite guidance systems have made conventional weapons nearly as destructive as small nuclear weapons.
They argue that lifting the ban on low-yield nuclear weapons will only undermine the US' ability to prevent the spread of such weapons to other countries.
"This just undermines our whole argument," said Senator Carl Levin of Michigan, the ranking Democrat on the Armed Services Committee.
"We're driving recklessly down a road that we're telling other people not to walk down," he said.