A test ban would not prevent an Iranian bomb, but it would make it far more difficult for Tehran to develop more advanced warheads that could be delivered by ballistic missiles. China, meanwhile, would require nuclear tests to deploy multiple warheads on its small arsenal of long-range missiles. The test ban would help in all these scenarios.
The United States stopped nuclear testing more than 20 years ago and has no need to do so ever again. Linton Brooks, former head of the National Nuclear Security Administration under President George W. Bush, said, "There's not going to be nuclear testing in the United States. No sane person thinks there is."
Despite this, the Senate has not yet provided its approval. As a result, the treaty cannot enter into force, the United States cannot take full advantage of its monitoring network, and the door to renewed nuclear testing by other nations remains open.
In the past, skeptics have claimed that the United States needs nuclear testing to maintain its nuclear arsenal or that our ability to verify test ban treaty compliance is not good enough. But the latest scientific evidence makes it clear that these concerns are misplaced.
Last year, a major National Academy of Sciences report concluded that the United States can maintain an effective nuclear arsenal without explosive testing. The study also found that the CTBT's verification network and U.S. monitoring capabilities have improved to levels better than predicted just a decade ago.
The global system is now more than 80 percent complete and succeeded in detecting North Korea's small nuclear tests in 2006, 2009 and this past week. With the CTBT fully in force, no potential violator could escape detection.
Five decades ago, President Kennedy feared that nuclear weapons would spread widely, but his fear has not been realized.
The main reason is the 1968 Non-Proliferation Treaty, or NPT, under which 190 nations pledged to stay nuclear weapons-free, in exchange for progress toward disarmament. The test ban is the only arms control measure mentioned in the NPT, and U.S. ratification of the test ban is seen as a litmus test of nuclear weapons states' commitment to pursue nuclear disarmament.
The CTBT has now been ratified by over 159 nations, including every one of our NATO allies. It is time for America to follow suit.
During his first term, President Obama repeatedly pledged to work to secure ratification of the test ban treaty. Now is the time for him to follow through. For its part, the Senate has a responsibility to consider the CTBT with an open mind, based on an up-to-date analysis.
Ratification will be challenging, but Republicans and Democrats understand the importance of common sense steps to reduce the nuclear threat.
Working together, they can create a lasting legacy for the country.
Jake Garn is a former U.S. senator for Utah; Ambassador Thomas Graham, Jr., is a former special assistant to the president for arms control, non-proliferation and disarmament.