Nuclear divergence between Britain and the United States: SDI and the Anti-Ballistic Missile Treaty

This article draws on recently declassified documents on both sides of the Atlantic to reveal the depth of the disagreements between Britain and the United States over adherence to the Anti-Ballistic Missile (ABM) Treaty during the 1980s. In the context of the radical Strategic Defense Initiative (SDI), the Thatcher government feared that the dismissive attitude of the Reagan administration towards the ABM Treaty would undermine the role of arms control in providing mutual security and would have harmful consequences for the viability of Britain's nuclear deterrent. Some British officials also suspected that the Reagan administration was manipulating alleged Soviet non-compliance with the Treaty as a pretext for abandoning it. The tensions between London and Washington on this issue were fundamental, as the Reagan administration perceived it as an obstacle which constrained the progress of SDI.