Explaining Britain’s vote to withdraw from the European Union (EU) has become something of a cottage industry since 2016. This is not only because of the importance of the decision but also because the United Kingdom’s long and bumpy relationship with “Europe” and the myriad dramatic events in the years prior to the referendum together offer commentators plenty of choice of potential causal explanations. In Europe and the Decline of Social Democracy in Britain: From Attlee to Brexit, Adrian Williamson points the finger squarely at the decline of social democracy as a dominant ideology of governance in Britain since the 1970s. In doing so, he attempts to explain “Brexit” with a neat hypothesis and engaging accounts of a half century’s worth of domestic party-political power struggles, chiefly in ideological terms. Herein lie both the book’s strengths, particularly as an ideological history, and its weaknesses, particularly as a robust explanation.

Williamson’s approach to testing his hypothesis aligns with the chapter layout. First, he characterizes the postwar period as a “golden age” of social democracy in British governance before chronicling its demise. Then, he describes pre-accession positivity to European Economic Community me