Does the proliferation of nuclear weapons cause ongoing conflicts to diminish or to intensify? The spread of nuclear weapons to South Asia offers an opportunity to investigate this crucial question. Optimistic scholars argue that by threatening to raise the cost of war astronomically, nuclear weapons make armed conflict in South Asia extremely unlikely. Pessimistic scholars maintain that nuclear weapons make the subcontinent war-prone, because of technological, political, and organizational problems. This book argues that nuclear weapons have destabilized the subcontinent, principally because of their interaction with India and Pakistan's territorial preferences and relative military capabilities. These findings challenge both optimistic and pessimistic conventional wisdom and have implications beyond South Asia.

This analysis questions President George W. Bush's reasons for refusing to follow a number of provisions of the U.S.-India Peaceful Atomic Energy Cooperation Act.

In his oral bill-signing statement to reporters and members of the public, President Bush praised the bill he was signing. He did not mention his disagreements with Congress on several of the provisions of the bill. However, in a separate written signing statement, he made clear that he, not Congress, conducts foreign policy and therefore has the greater say on what that policy should be. He declared: "Given the Constitution's commitment to the presidency of the authority to conduct the Nation's foreign affairs, the executive branch shall construe such policy statements as advisory." Thus, he concluded, he will not follow some of the provisions of the new statute: "My approval of the Act [by signing it] does not constitute my adoption of the statements of foreign policy in the Act as U.S. foreign policy."

For a long time, how nuclear facilities were protected from terrorists and thieves has been largely the prerogative of the facilities themselves or individual governments. But the September 11 terrorist attacks and statements by Osama bin Laden have raised new concerns about preventing terrorists from stealing or attacking nuclear material that is often not well protected. As a result, new international standards have been adopted, calling on states to provide stronger protection for nuclear material.

So far, however, these standards are very general and lack effective enforcement. To remedy these shortcomings, the UN Security Council should consider such measures as providing a greater role for the International Atomic Energy Agency (IAEA).

At their meeting in India in July of 2005, President George W. Bush and Indian Prime Minister Manmohan Singh agreed that the United States and India should resume cooperation in peaceful nuclear energy matters. Their cooperation had ended in 1974 after the Indians conducted a nuclear explosion which the United States concluded was a nuclear weapon test. After achieving a tentative agreement with Prime Minister Singh, Bush called upon Congress to amend the Atomic Energy Act's prohibition on U.S. nuclear assistance to India so that he could carry out the agreement. Before the end of its 2006 session, Congress did so. It approved a bill authorizing the negotiation of a new U.S.-India nuclear cooperation agreement. The authorization was not a "blank check." In this new statute, Congress insisted upon having an opportunity for reviewing whatever final agreement the administration negotiates with India. It demanded that, before it considers whether to give approval to that agreement, the agreement be submitted for approval to both the IAEA and to the international Nuclear Suppliers Group (NSG).

On Oct. 31 to Nov. 4, 2006, a delegation led by Prof. John W. Lewis, Stanford University, accompanied by Siegfried S. Hecker and Robert L. Carlin of Stanford University, and Charles L. (Jack) Pritchard of the Korean Economic Institute visited Pyongyang, Democratic People's Republic of Korea (DPRK). This report summarizes the findings regarding the DPRK nuclear program based on our discussions with officials from the Ministry of Foreign Affairs, the Korean People's Army, the Supreme People's Assembly, and the Yongbyon Nuclear Scientific Research Center. Three members of our delegation made similar visits to the DPRK in January 2004 and August 2005. Before and after the current trip to the DPRK, Lewis and Hecker also had extensive discussions about the DPRK nuclear program with Chinese officials from the Ministry of Foreign Affairs, the military, the Central Party School, the China Reform Forum, the China National Nuclear Corporation, and the Institute of Applied Physics and Computational Mathematics.

This article presents a review of the sensitivities to proliferation attempts in each of the different stages of the commercial nuclear fuel cycle and within the nuclear power industry. As the global nuclear power industry may be on the brink of a major expansion that might rival its original growth at the inception of the nuclear age, the question is: Would this second expansion create uncontrollable proliferation risks in its wake? The basic answer is that the nuclear power industry in itself does not pose a direct proliferation threat; however, various elements of the nuclear fuel cycle could create different proliferation sensitivities if not safeguarded carefully. The first element of securing the nuclear fuel cycle is the understanding of which elements pose the greatest potential for successful proliferation attempts. These issues and several institutional and technical mitigation strategies to reduce the potential for possible proliferation are discussed here.

If the ultimate terror attack were to happen--a nuclear explosion in a city--the resulting death and destruction would be almost unimaginable. But we can imagine the geopolitical consequences. Can we do anything now that would help matters? Michael May, Jay Davis and Raymond Jeanloz argue that we can, by establishing a databank of known nuclear explosive materials. Using this resource it would be possible to establish where the materials came from and who was responsible for the terrorist act. Not just for purposes of retribution, but in order to assess the chances of further nuclear detonations.

We develop a mathematical model to find the optimal inspection strategy for detecting a nuclear weapon (or nuclear material to make a weapon) from being smuggled into the United States in a shipping container, subject to constraints of port congestion and an overall budget. We consider an 11-layer security system consisting of shipper certification, container seals, and a targeting software system, followed by passive (neutron and gamma), active (gamma radiography), and manual testing at overseas and domestic ports. Currently implemented policies achieve a low detection probability, and improved security requires passive and active testing of trusted containers and manually opening containers that cannot be penetrated by radiography. The annual cost of achieving a high detection probability of a plutonium weapon using existing equipment in traditional ways is roughly several billion dollars if testing is done domestically, and is approximately five times higher if testing is performed overseas. Our results suggest that employing high-energy x-ray radiography and elongating the passive neutron tests at overseas ports may provide significant cost savings, and several developing technologies, radiation sensors inside containers and tamper-resistant electronic seals, should be pursued aggressively. Further effort is critically needed to develop a practical neutron interrogation scheme that reliably detects moderately shielded, highly enriched uranium.

To reduce the risk of nuclear terrorism, we must prevent terrorists from obtaining nuclear weapons or materials. This will require, among other things, a sustained effort to keep dangerous nations from going nuclear--in particular North Korea. This article reviews the efforts the United States has undertaken through the years to keep North Korea from building a nuclear arsenal, arguing that the history of proliferation on the Korean Peninsula is marked by five nuclear crises. A sixth could be on the horizon, further compromising American efforts to lessen the likelihood of a nuclear attack on U.S. soil.