Vive le Bomb? US May Alter Its Stance on Nuclear Tests

WHILE governments across Asia and Europe lambaste France for its decision to resume nuclear-weapons tests after a three-year moratorium, the Clinton administration has been noticeably restrained.

Arms-control experts say they can explain why President Clinton expresses only mild "regret" over France's announcement that it will set off eight nuclear blasts at its South Pacific test site: The White House may also change its stance on nuclear testing. Such a move might deal a fatal blow to efforts in Geneva to forge a global ban on nuclear tests by the end of 1996.

"We are unwilling to be forthright with the French because there are indications that we ourselves are poised to take a decision that would be even more destructive to the Comprehensive Test Ban Treaty [CTB]," says Jack Mendelsohn, deputy director of the Washington-based Arms Control Association.

The CTB would be the next milestone toward global nuclear disarmament following the indefinite extension of the Nuclear Non-Proliferation Treaty (NPT) by 175 countries in May. The 25-year-old NPT has been the key restraint on the spread of atomic arms.

At issue in the United States are the limits on the power - or yield - of small, experimental blasts that would still be allowed by the CTB. The US is advocating at the United Nations-sponsored Conference on Disarmament in Geneva a "threshold" of no more than the equivalent of four pounds of TNT. This limit would allow the "declared" nuclear-weapons states - the US, China, Russia, Britain, and France - to pursue computer-based research.

But some Pentagon officials and weapons designers are pressing the administration to raise its proposed yield threshold to between 300 tons and 500 tons of TNT. (The atomic bomb dropped on Hiroshima, Japan, in 1945 had the force of 14,000 tons of TNT). These officials believe a higher threshold is needed to allow periodic underground blasts to test the reliability of US nuclear stockpiles. The US is observing the same 1992 test moratorium that France is preparing to break.

A senior administration official says the issue is being debated "at the working level" and that "only the president" can make a final decision. "What we are doing is what I would hope the American people would want us to do: We are assessing the pros and cons."

But by going to a higher test threshold, the US could doom the Geneva talks. Should the US embrace a higher limit, experts say, it would be joined by the other nuclear powers, a development that some nonnuclear states would not accept.

"The impact would be to blow up the CTB negotiations on the heels of the French decision to resume testing," says Michael Krepon, a nuclear-arms-control expert and president of the Henry L. Stimson Center, a Washington think tank.

Says the administration official: "You could have the possibility that the [nuclear states] could reach a decision among themselves that the rest of the Conference on Disarmament would not accept."

A 1994 study showed that computers can test the reliability of US nuclear stockpiles at much lower costs, Dr. Krepon says. He suspects that advocates may be seeking a higher threshold so research can go ahead on a new breed of small, advanced warheads known as "exotic nukes" or "mini-nukes."

Arms-control experts say a change in US position on the CTB would, like the French testing decision, be considered a grave breach of faith by the nonnuclear weapons states. Under the NPT, the US, France, Russia, China, and Britain promised to exercise "maximum restraint" in nuclear-weapons tests.

Only four days after joining the May 11 vote to extend the NPT, China detonated a nuclear device, but said it remains committed to the CTB negotiations.

Similarly, France says that it will conclude its tests by the fall of 1996 and then sign the CTB.