The Logic of the Test Ban Treaty

Daryl G. Kimball

In his stirring April 5 speech in Prague, President Barack Obama outlined his vision for strengthening global efforts to curb the spread of nuclear weapons and moving forward on practical, immediate steps "to seek the peace and security of a world without nuclear weapons." Appropriately, his short list of such steps includes re-establishing U.S. leadership on the achievement of a global, verifiable ban on nuclear weapons testing. Obama pledged to "immediately and aggressively pursue U.S. ratification of the Comprehensive Test Ban Treaty [CTBT]."

Indeed, the CTBT remains an essential part of a commonsense strategy to reduce nuclear dangers. By banning the bang, the CTBT constrains the ability of nuclear-armed states to perfect new and more sophisticated warheads. For instance, without additional testing, China cannot perfect the technology to arm its missiles with multiple warheads.

Further, the CTBT can help de-escalate regional nuclear tensions. Ratification by Egypt, Iran, and Israel would reduce nuclear weapons-related security concerns and bring those states further into the nonproliferation mainstream. The Indian-Pakistani rivalry could be eased by converting their unilateral test moratoria into a legally binding commitment to end nuclear testing.

In addition, national and international capabilities to detect and deter possible clandestine nuclear testing by other states will be significantly greater with the CTBT in force. U.S. ratification also is essential to spur action by the eight other states whose ratification is required for entry into force.

Unfortunately, the Senate declined to give its advice and consent to ratification when it briefly considered the treaty in October 1999. Many senators who voted "no" expressed concerns about the ability of the United States to maintain its arsenal in the absence of testing and to verify compliance with the treaty.

That was then, and this is now. There is neither the need nor the political support for renewed U.S. testing for any reason, and it is in the interest of national security to prevent testing by others. Even though the United States has already assumed most CTBT-related responsibilities, it cannot reap the full security benefits of the CTBT until the Senate approves the treaty by a two-thirds majority.

Nevertheless, some pro-testing senators will try to urge their colleagues not to reconsider the CTBT. That would be a mistake. The security value of the CTBT is greater than ever, and significant technical advances address earlier concerns about the treaty.

As George Shultz, former secretary of state under President Ronald Reagan, said April 17 in Rome, his fellow Republicans "might have been right voting against it some years ago, but they would be right voting for it now, based on these new facts." During his 2008 campaign, Sen. John McCain (R-Ariz.) said that if elected president, he would take "another look" at the CTBT.

Another look at the scientific evidence will show that advances in the Stockpile Stewardship Program have significantly increased confidence in the reliability of the existing U.S. arsenal. As a result, more is known today than ever before about the nuclear weapons arsenal, and confidence in the ability to maintain the warheads is increasing at a faster rate than the uncertainties.

For example, the Department of Energy announced in 2006 that studies by Lawrence Livermore and Los Alamos National Laboratories show that the plutonium primaries, or pits, of most U.S. nuclear weapons "will have minimum lifetimes of at least 85 years," which is about twice as long as previous official estimates.

Contrary to the myth perpetuated by some CTBT critics, maintaining the reliability of proven U.S. nuclear warhead designs does not depend on a program of nuclear test explosions. Instead, the existing U.S. nuclear arsenal has been maintained and modernized through non-nuclear tests and evaluations, combined with the replacement or remanufacture of key components to previous design specifications.

Since 1994, a rigorous certification process has determined each warhead type in the U.S. nuclear weapons arsenal to be safe and reliable. Life Extension Programs have successfully modernized major warhead types in the arsenal and stretched out their effective service life for decades to come.

According to weapons physicist Richard Garwin, the new evidence on the longevity of weapons plutonium "has removed any urgency to engineer and manufacture new design replacement warheads." Garwin says the continued performance of legacy warheads can be more reliably certified than new ones.

Test ban monitoring and verification capabilities have also improved. As the July 2002 National Academy of Sciences panel report documents, with the combined capabilities of the International Monitoring System, national technical means, and civilian seismic networks, no potential CTBT violator can be confident that a nuclear explosion of any military utility would escape detection.

The time has come to reconsider and ratify the CTBT. With Obama's leadership, bipartisan support from opinion leaders, and significant improvements in the ability to maintain the U.S. nuclear arsenal and detect nuclear test explosions, the case for the CTBT is stronger than ever.