On October 13 the US Senate saw fit not to ratify the Comprehensive Test Ban Treaty. This made me sad, both for my country and for the world. I believe that it was a serious mistake both because the CTBT would have been good in itself and because I believe that the failure to ratify the treaty will have serious consequences for American foreign policy for years to come.

Fifty-four years ago I watched from a distance as the work we had done at Los Alamos was verified in the Trinity test. This was a necessary test for us. We did not know whether the device we had invented, designed, and built would explode. Like others who had worked on the atomic bomb, I was exhilarated by our success—and terrified by the event. A few weeks later atomic bombs were dropped on Hiroshima and Nagasaki. Fortunately, none has been dropped on an adversary since then.

I assume we want to keep it that way. One of the key elements in achieving this is for as few countries as possible to possess nuclear weapons technology. Another is maintaining the capacity to respond to any who attempt to use it.

The effort to get a comprehensive test ban treaty has a long history in this country. The basic purpose of a test ban is straightforward. On the one hand it would help curb proliferation, that is, the spread of atomic and nuclear weapons to additional countries. On the other it slows or stops the nuclear arms development race among existing nuclear powers.

In 1958, the President’s Science Advisory Committee, of which I was a member, suggested to President Eisenhower that he propose a ban on tests of nuclear weapons. Eisenhower accepted our suggestion, and was joined by both of the other then-existing nuclear powers, the Soviet Union and Great Britain, in seeking such a ban. In 1961, Eisenhower said that one of his chief regrets upon leaving office was that this had not been achieved. Every administration since has had a stated goal of working for a comprehensive test ban treaty.

A scientific conference involving scientists from the three nuclear powers was held in 1958 to investigate the feasibility of a test ban. The conference determined that the process for detecting underground tests of weapons with an explosive power lower than 20 kilotons was unreliable. (For comparison, the Trinity test and the two bombs dropped in World War II had yields of between 15 and 25 kilotons.) Today reliable detection is possible for tests with explosive power as low as approximately one kiloton. The 1958 conference led to a treaty banning atmospheric nuclear weapons testing in 1962.

Opponents of the Comprehensive Test Ban Treaty have now raised three basic objections to it. First, those who wish to continue nuclear weapons development believe, correctly, that new weapons need to be tested in order to discover whether they work. Second, while the CTBT prohibits any testing whatever—“zero tolerance”—there might be small-scale tests that could not reliably be detected. Third, occasional tests may be required as part of the process of maintaining our own stockpile. I would like to address each of these objections briefly.

Everyone concerned should realize that a test ban treaty is strongly in favor of the United States. We have a substantial lead in nuclear weapons technology over all other countries. We have tested weapons of all sizes and shapes suitable for military purposes. We have no need for further development of nuclear weapons through testing.

A test ban would make it extremely difficult for new nuclear powers to emerge. In testimony before the Senate Foreign Relations Committee, Richard Garwin, a distinguished physicist with long experience in arms control, pointed out that under ideal conditions we could now detect tests with nuclear yields as low as one pound! Under almost all conditions, tests of weapons with more than a one-kiloton yield can be reliably detected. The CTBT provides for an extensive increase in test-monitoring stations, which would improve the ability to detect nuclear tests anywhere in the world.

Opponents of the CTBT have made much of the possibility of undetectable tests by rogue countries. But it is extremely difficult to build a workable nuclear weapon whose yield could be relied on to stay beneath the detection threshold. Even if a new nuclear power did build and test a nuclear weapon that escaped detection, the test would provide far less information than would be gained from testing a much-easier-to-build, and highly destructive, 5- to 20-kiloton bomb. Tests of that magnitude can be detected. Always. The information from a low-yield test that was undetectable would be of essentially no help in the development of a hydrogen bomb capable of destroying a large city. For the existing nuclear powers such very-low-yield tests would provide no useful information.

Thus the powers that could build weapons capable of escaping detection have no incentive to do so. And the countries that might gain minimally useful information from such tests are unlikely to be able to build the low-yield weapon.


We now have a large stockpile of nuclear weapons of all imaginable types. Of course this stockpile must be preserved through careful stewardship. This is one of the primary occupations of the national atomic laboratories, to which I continue to be a consultant.

Preservation of existing weapons is a very different matter from the design of new ones. We already know that the bombs we have work. The problem is to make sure that their various components have not deteriorated with the passage of time. This can be done without nuclear tests through a com-bination of sophisticated inspection techniques and computer simulation, two methods that enable us to see whether the observed effects of time affect a weapon’s effectiveness. If any component shows signs of deterioration, it is refabricated. If the nuclear fuel itself is becoming degraded, the fuel can be remachined. It is well established that, with existing apparatus, the efficacy of the refabricated units can be proved by sophisticated non-nuclear tests. We do not need explosive tests to prove that these weapons work.

The key to the process of stewardship, however, is people. For the stewardship to be successful, the national laboratories need to recruit and retain top-flight scientists and engineers. The working environment at the labs must promote trust and stability. The head of one of the labs has testified, in essence, that with current personnel he could promise to maintain the nuclear stockpile’s integrity without testing but that he would not be able to promise this in ten years if the present environment of constant budget cuts and witch hunts continues. I believe, moreover, that if the quality of our personnel diminishes, he could not promise to maintain the stockpile’s integrity even with tests.

Thus, on close examination, the objections raised to the CTBT are not valid. We do not need to test new developments in nuclear arms since we are no longer in an arms development race. We have won it and the test ban would help preserve our advantage. While it is true that some tests might successfully be hidden by would-be nuclear powers, the tests that could reliably be hidden would be so small that they would not be helpful, especially for the development of thermonuclear weapons. And we do not need testing in order to maintain the stockpile as long as the government properly supports the stewardship program.

I believe that the rejection of the CTBT will hurt our country in more important ways. The treaty still needed the signatures of twenty-one “nuclear capable” nations to go into force and, with the defeat in the Senate, the chances of getting further agreement have been badly damaged. The United States has lost credibility in matters of arms control. It will take a long time before the US can regain leadership in this field. This is particularly serious because most of the ideas in arms control have come from America.

The most important current arms control initiative is START, the reduction in the number of strategic nuclear weapons from the absurd level of about six thousand both for the US and Russia. START was begun by President Reagan and is far more important than the test ban. It holds out the prospect that the largest and most dangerous stocks of nuclear weapons will be reduced to the minimum necessary for deterrence. Who will now take the lead in carrying it forward? Russia, which is struggling for political and economic existence? One of our NATO partners, such as Great Britain or France, which have relatively small nuclear arsenals, or Germany, which has none? China?

The vote against the test ban treaty undermines the entire future of arms control. It is a decision that should be reversed.

October 21, 1999

This Issue

November 18, 1999