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– Frank von Hippel
Co-Director of Program on Science and Global Security, Princeton University
June 1, 2018
UK-U.S. Set to Extend Nuclear Pact

Kerry Boyd-Anderson

U.S. and British officials decided in June to extend an agreement that allows the exchange of nuclear weapons information between the two countries. Some critics are concerned, however, that the agreement undermines nonproliferation efforts and could lead to the development of new nuclear weapons.

On June 14, U.S. Assistant Secretary of State for Arms Control Stephen Rademaker and his British counterpart, F. R. Baker, signed an amendment to extend the 1958 Mutual Defense Agreement (MDA) for another 10 years.

Under the Atomic Energy Act, Congress has 60 legislative days to raise any objection to the agreement. To date, no such objections have yet been registered. A Senate Foreign Relations Committee spokesperson said Aug. 16 that no hearings on the matter have been scheduled.

The amendment also was sent to the British Parliament for consideration over a 21-day period, but the Parliament decided not to raise any objections or hold any inquiries, despite a request by several members of Parliament for an open debate. The British government said that it will consider the agreement ratified if the United States does. The agreement will expire Dec. 31 unless ratified by both countries.

The MDA, formally known as the 1958 Agreement between the United Kingdom and the United States for Co-operation on the Uses of Atomic Energy for Mutual Defense Purposes, allows the two countries to exchange information on nuclear weapons, including their design, and to transfer materials and equipment related to nuclear weapons and their delivery systems. The MDA also permits the transfer of plutonium and highly enriched uranium. It does not allow the two countries to transfer actual nuclear weapons to each other, which is prohibited under Article I of the nuclear Nonproliferation Treaty.

In 1958 the leaders of both countries touted the agreement as a way to improve the capabilities of their nuclear weapons programs. The British Atomic Weapons Establishment has called the MDA “a cornerstone of life for the British nuclear weapon community.” The agreement has played a particularly important role in maintaining the British nuclear arsenal. In a June 14 message to Congress, President George W. Bush highlighted continued close Anglo-American cooperation and the United Kingdom’s participation in NATO as reasons for extending the agreement.

Some critics, however, say the two countries should not automatically extend the agreement. British critics have expressed concern that the Bush administration has plans to develop new nuclear weapons, such as low-yield nuclear weapons and robust nuclear earth penetrators. They say that the British agreement to extend the MDA without seriously considering its potential implications would imply British support for U.S. efforts to design new nuclear weapons and might also lead the United Kingdom to participate in research and development of new weapons. The British government has said that it is not involved in research and development of “low yield” and “bunker-buster” nuclear weapons.