Arms-Control Integrity on the Line : U.S. Actions on Threshold Treaty Cost Us the Moral Ground

The United States and the Soviet Union signed the Threshold Test Ban Treaty in 1974, but no American President has ever submitted the treaty, which restricts underground nuclear explosions to a yield below 150 kilotons, to the Senate for ratification.

This record has raised doubts about the U.S. role, and even motives, as a negotiating partner in arms control. It stands in sharp contrast to recent Soviet flexibility and initiatives, and we face a challenge to action if we are not to lose to them the moral high ground in arms control.

The Bush Administration now has an opportunity to review the reasons for procrastination given by its predecessors. The ostensible reason for non-ratification given repeatedly by the Ronald Reagan Administration was that we could not measure the treaty’s 150-kiloton threshold very accurately--thus constituting an unacceptable risk.

But this makes no sense. When President Richard M. Nixon signed the treaty, seismologists had concluded that the 150-kiloton threshold could be measured by existing U.S. instruments outside the Soviet Union to “within a factor of two.” This means that if the Soviets attempted to cheat by releasing nuclear blasts at 300 kilotons, the United States would detect a violation 95% of the time. They might get away with cheating by a much smaller amount, but not one of military or technical significance to either the United States or the Soviet Union. (The 150-kiloton limit, observed by both countries despite the lack of ratification, was established to satisfy the weapons designers; explosions can be detected and identified at yields 10 to 20 times smaller.)

Thus Nixon agreed that verification technology in 1974 was adequate to remove any risk to U.S. security from Soviet cheating. Since 1974, seismologists have improved their instruments and methods of analysis. The “factor of two” uncertainty of 1974 has been reduced to less than a factor of 1.5. Even so, the Reagan Administration insisted that this was not good enough, and that further, more intrusive observations were necessary.

In response, the Soviets gave in and agreed to talks on improving verification. Initially the Soviets wanted to talk both about laying the technical groundwork for reducing the allowed yields below the 150-kiloton threshold and about more precise measurements of the treaty’s limit. We insisted on talking only about use of the so-called CORRTEX method of verification, proposing it as a “direct” yield measurement. The Soviets maintained that CORRTEX, which measures the yield of an explosion by determining the speed at which the shock arrives at a nearby test hole, was no better than the less-intrusive seismic observation, but gave in by agreeing to the joint verification experiments to be carried out, using both the seismic and CORRTEX methods, in Siberia and Nevada.

These tests have now been concluded, in itself a remarkable exhibition of the new cooperation between Washington and Moscow. But now, according to published reports, the United States is refusing to release the data obtained from the joint tests even though the Soviets have proposed to do so.

This sequence paints an embarrassing picture of American conduct:

--We are refusing, giving patently invalid and contrived reasons, to ratify a treaty signed by a U.S. President 15 years ago.

--We are refusing technical information to the American people that we are sharing with the Soviets.

--We seem to find it difficult to accept “yes” for an answer when negotiating with the Soviets.

In the early ‘70s, the situation was reversed. The Soviets were intransigent negotiators, obsessed with secrecy. Now, in the view of many world observers, particularly in Europe, the United States is in the role of the heavy in the arms-control process.

Why is all this occurring? Do the results of the joint experiments contradict the U.S. positions? Could the data show that indeed, CORRTEX is not enough more precise than more-remote seismic measurements to warrant its greatly increased intrusiveness? Do some of the signals from U.S. explosions exceed the allowed limit by a small amount in the same way as some Soviet tests led President Reagan to charge that they were “likely to have violated the treaty?”

The issue we are discussing here is not whether or when the permitted explosions should be lowered in size or stopped altogether. The issue is the integrity of the United States as a negotiating partner in arms control and the responsibility of the U.S. government to inform its own citizens on technical facts we are sharing with the Soviets.

Frank Gaffney, Reagan’s deputy assistant secretary of defense, has written: “The more time wasted on discussions and experimentation of (yield) monitoring techniques irrelevant to . . . complete prohibition of legal nuclear tests, the easier it will be to stave off demands for the more constraining comprehensive test ban.” Does the Bush Administration wish to continue the pursuit of arms control in this spirit?

We suggest that the President immediately release the data on the Nevada-Siberia experiments, whether they do or do not support past positions; submit the Threshold Test Ban Treaty to the Senate for consent to ratification, and continue the joint verification experiments to calibrate the seismic methods with CORRTEX, looking forward to measurements oflower-yield explosions.

These steps will recapture some of the moral ground in arms control that have been lost to the Soviets in view of the unfortunate record of the Threshold Test Ban Treaty cited here.