Guest Post: Scientists Report on the Comprehensive Nuclear Test-Ban Treaty

This is a guest post by CFR senior fellow Frank Klotz.

The National Research Council (NRC) released its long-awaited update on the Comprehensive Nuclear Test-Ban Treaty (CTBT) last Friday. Given the renown of the scientists and former officials who authored the report, it is likely to have an important impact on the longstanding debate over whether the United States should ratify the CTBT.

The report itself concludes that over the past decade the United States has significantly improved the technical capabilities needed both to maintain a reliable nuclear weapon stockpile without nuclear explosion testing and to detect clandestine testing by others. By thus addressing two of the major concerns raised when the treaty was rejected by the Senate in 1999, the report clearly strengthens the position of those who favor ratification now.

The CTBT prohibits states from carrying out “any nuclear weapon test explosion or any other nuclear explosion.” It also lays out in great detail the means for monitoring compliance, including the establishment of a worldwide network of more than 300 detection stations and provisions for on-site inspection. Interestingly, the treaty does not specifically define “nuclear explosion.” The United States and the other major nuclear powers have consistently held that the CTBT is a “zero yield” treaty. In other words, it bans weapon tests that produce a self-sustaining, fission chain reaction; but, it does not preclude weapon experiments that do not. Such experiments—and the subsequent analysis performed on increasingly powerful computers—have played a critical role in assessing the health of the nuclear weapons stockpile since the United States unilaterally stopped testing in 1992.

For the CTBT to actually enter into force, it must be ratified by all forty-four nations that possessed nuclear power or research reactors and participated in the treaty negotiations from 1994 to 1996. Of these, only eight have not yet done so:  China, Egypt, Iran, Israel, India, Pakistan, North Korea, and the United States. Ironically, the United States played a leading role in negotiating the treaty, and President Clinton was the first world leader to sign it in 1996. However, when the Senate formally considered ratification three years later, treaty proponents failed to muster the necessary two-thirds vote. It has languished in political limbo ever since.

The Obama administration signaled early on that it intended to renew efforts to ratify the treaty as part of a broader agenda to curb the proliferation of nuclear weapons and to prevent nuclear terrorism. In the wake of the successful, but politically contentious approval of the U.S.-Russian New Strategic Arms Reduction Treaty (New START), senior officials openly acknowledged that a renewed Senate debate over CTBT would likely be “spirited.” Accordingly, they have avoided setting a time table for taking up the treaty and concentrated instead on laying the groundwork for a push when the time seems right. With this objective in mind, the Obama administration has publicly emphasized the merits of the treaty, as well as the steps taken to mitigate previously-expressed concerns about monitoring compliance and ensuring the continued reliability of the U.S. nuclear weapon stockpile without explosive testing.

While the NRC report avoids taking a policy position on treaty ratification, it notes that these steps have been even more effective than originally anticipated. It concludes in fact that “the United States is now in a better position than at any time in the past to maintain a safe and effective nuclear weapon stockpile without testing and to monitor clandestine nuclear testing abroad.” This is very encouraging news for treaty supporters.

The NRC report is, however, unlikely to persuade the more ardent opponents of the treaty. They argue that U.S. ratification will do little to eventually bring the treaty into force since some of the remaining hold-outs—such as Iran or North Korea—will probably not follow suit. They also contend that ratification will hardly dissuade nations who feel it is in their best interest to develop nuclear weapons or to improve the ones they already have. Finally, they assert that the United States may ultimately need to resume testing to ensure the reliability of existing nuclear weapons, or eventually to replace them in order to satisfy new strategic requirements.

In reality, the U.S. has refrained from nuclear explosive testing for nearly twenty years. Successive administrations of both parties have determined a unilateral testing moratorium to be U.S. policy. Absent a radical change in the international environment, the political barriers to a resumption of testing would be practically insurmountable. While the United States probably garners some credit for exercising this self-imposed restraint, it is likely to be in a far better position to rally international pressure against would-be proliferators and to constrain regional arms races if it joined the 157 nations who have already ratified the CTBT.

Most treaties have a “supreme national interest clause” that allow nations to opt out if fundamental conditions change. The CTBT is no exception. So, if the direst predictions of its opponents did in fact come true, there are provisions within the treaty itself for withdrawal. In the meantime, it only makes sense to seek maximum diplomatic leverage for something the United States is already doing anyway by ratifying the treaty.

Frank Klotz is a Senior Fellow for Strategic Studies and Arms Control at the Council on Foreign Relations, and the former commander of Air Force Global Strike Command.