Washington Times
October 12, 1999

Oct. 6, 1999

Dear Sens. Lott and Daschle:

As the Senate weighs whether to approve the Comprehensive Test Ban Treaty (CTBT), we believe senators will be obliged to focus on one dominant, inescapable result were it to be ratified: over the decades ahead, confidence in the reliability of our nuclear weapons stockpile would inevitably decline, thereby reducing the credibility of America's nuclear deterrent. Unlike previous efforts at a CTBT, this treaty is intended to be of unlimited duration, and though "nuclear weapon test explosion" is undefined in the treaty, by America's unilateral declaration the accord is "zero-yield," meaning that all nuclear tests, even of the lowest yield, are permanently prohibited

. The nuclear weapons in our nation's arsenal are sophisticated devices, whose thousands of components must function together with split-second timing and scant margin for error. A nuclear weapon contains radioactive material, which in itself decays and also changes the properties of other materials within the weapon. Over time, the components of our weapons corrode and deteriorate, and we lack experience predicting the effects of such aging on the safety and reliability of the weapons. The shelf-life of U.S. nuclear weapons was expected to be some 20 years. In the past, the constant process of replacement and testing of new designs gave some assurance that weapons in the arsenal would be both new and reliable. But under the CTBT, we would be vulnerable to the effects of aging because we could not test "fixes" of problems with existing warheads

. Remanufacturing components of existing weapons that have deteriorated also poses significant problems. Manufacturers go out of business, materials and production processes change, certain chemicals previously used in production are now forbidden under new environmental regulations, and soon. It is a certainty that new processes and materials -- untested -- will be used. Even more important, ultimately the nuclear "pits" will need to be replaced -- and we will not be able to test those replacements. The upshot is that new defects may be introduced into the stockpile through remanufacture, and without testing we can never be certain that these replacement components will work as their predecessors did

. Another implication of a CTBT of unlimited duration is that over time we would gradually lose our pool of knowledgeable people with experience in nuclear weapons design and testing. Consider what would occur if the United States halted nuclear testing for 30 years. We would then be dependent on the judgement of personnel with no personal experience either in designing or testing nuclear weapons. In place of a learning curve, we would experience an extended unlearning curve

. Furthermore, major gaps exist in our scientific understanding of nuclear explosives. As President Bush noted in a report to Congress in January 1993, "Of all U.S. nuclear weapons designs fielded since 1958, approximately one-third have required nuclear testing to resolve problems arising after deployment." We were discovering defects in our arsenal up until the moment when the current moratorium on U.S. testing was imposed in 1992. While we have uncovered similar defects since 1992, which in the past would have led to testing, in the absence of testing, we are not able to test whether the "fixes" indeed work

. Indeed, the history of maintaining complex military hardware without testing demonstrates the pitfalls of such an approach. Prior to World War II, the Navy's torpedoes had not been adequately tested because of insufficient funds. It took nearly two years of war before we fully solved the problems that caused our torpedoes to routinely pass harmlessly under the target or to fail to explode on contact. For example, at the Battle of Midway, the U.S. launched 47 torpedo aircraft, without damaging a single Japanese ship. If not for our dive bombers, the United States would have lost the crucial naval battle of the Pacific war

. The Energy Department has structured a program of experiments and computer simulations called the Stockpile Stewardship Program, that it hopes will allow our weapons to be maintained without testing. This program, which will not be mature for at least 10 years, will improve our scientific understanding of nuclear weapons and would likely mitigate the decline in our confidence in the safety and reliability of our arsenal. We will never know whether we should trust Stockpile Stewardship if we cannot conduct nuclear tests to calibrate the unproven new techniques. Mitigation is, of course, not the same as prevention. Over the decades, the erosion of confidence inevitably would be substantial

. The decline in confidence in our nuclear deterrent is particularly troublesome in light of the unique geopolitical role of the United States. The U.S. has a far-reaching foreign policy agenda and our forces are stationed around the globe. In addition, we have pledged to hold a nuclear umbrella over our NATO allies and Japan. Though we have abandoned chemical and biological weapons, we have threatened to retaliate with nuclear weapons to such an attack. In the Gulf war, such a threat was apparently sufficient to deter Iraq from using chemical weapons against American troops

. We also do not believe the CTBT will do much to prevent the spread of nuclear weapons. The motivation of rogue nations like North Korea and Iraq to acquire nuclear weapons will not be affected by whether the United States tests. Similarly, the possession of nuclear weapons by nations like India, Pakistan and Israel depends on the security environment in their region not by whether the U.S. tests. If confidence in the U.S. nuclear deterrent were to decline, countries that have relied on our protection could well feel compelled to seek nuclear capabilities of their own. Thus, ironically, the CTBT might cause additional nations to seek nuclear weapons

. Finally, it is impossible to verify a ban that extends to very low yields. The likelihood of cheating is high. "Trust but verify" should remain our guide. Tests with yields below 1 kiloton can both go undetected and be militarily useful to the testing state. Furthermore, a significantly larger explosion can go undetected -- or mistaken for a conventional explosion used for mining or an earthquake -- if the test if "decoupled." Decoupling involves conducting the test in a large underground cavity and has been shown to dampen an explosion's seismic signature by a factor of up to 70. The United States demonstrated this capability in 1966 in two tests conducted in salt domes at Chilton, Miss

. We believe these considerations render a permanent, zero-yield Comprehensive Test Ban Treaty incompatible with the nation's international commitments and vital security interests and believe it does not deserve the Senate's advice and consent. Accordingly, we respectfully urge you and your colleagues to preserve the right of this nation to conduct nuclear tests necessary to the future of our nuclear deterrent by rejecting approval of the present CTBT.

Respectfully,

James R. Schlesinger, Richard B. Cheney, Frank C. Carlucci, Caspar W. Weinberger, Donald H. Rumsfeld and Melvin R. Laird