Writing a book about a moving target is always a high-risk strategy, let alone in conditions of speeded-up politics like the present. It is quite possible that by the time the present volume is published there will have been further sea-changes in Britain's relationship with the European Union as the result of the volatile interactions between the Article 50 negotiations and domestic politics. But how can I not write about such an important subject as my country's decision to leave the most significant cooperative endeavour yet created by sovereign states in favour of an unknown voyage on the open seas of international politics? This is especially the case given that the flood of writing which Brexit has engendered is in large part concerned with the issues – vital as they are – of economics, sovereignty, migration and the Irish border? Foreign policy has been relatively neglected, even though the professionals in government, and those outside who follow these things, know that the decision to leave the EU represents a foreign policy shift of the first magnitude, both in the general sense of our ‘place in the world’ and technically, in terms of the policy-making process. These issues too need serious discussion.

I have been writing about British foreign policy for all my professional life, which has coincided almost exactly with the United Kingdom's membership of the EC/EU. For much of the time I have also focused on Europe's attempts to coordinate national foreign policies so as to ‘speak with one voice’ in relations with third parties. I have always been sceptical of the view that a European superpower could and should be created but at the same time have recognized that Britain's ability to influence events alone is increasingly limited. This is the starting-point of the analysis in this short book, which seeks to be even-handed in assessing the dilemmas facing British foreign policy as a result of the referendum vote in 2016, but at the same time argues that – in or out of the EU – we are first and foremost a European power. What happens in Europe and its neighbourhood is both a major concern for the UK and the theatre in which our foreign policy is most likely to be effective.

In order to limit the vulnerability of the book to new events I have chosen an historical and thematic approach. This places UK foreign policy in the context of Britain's gradual, often reluctant, move towards the project of European integration, showing that foreign policy was the only area in which it was ‘present at the creation’, and which (not coincidentally) turned out to cause fewest clashes with other Member States. The book analyses in Chapter 3 the nature of the system of cooperation in classical diplomacy known first as European Political Cooperation and then as the Common Foreign and Security Policy, showing that it allowed Britain to enjoy both influence and independence. The discussion then opens up to focus on the wider concept of ‘external relations’, which includes such things as monetary diplomacy, enlargement policy, security in the broadest sense and migration. Here the UK has been able to pursue, with relative success, what I term an à la carte approach, opting in to some common systems and opting out of others.

Moving back towards a macro perspective, that of how Britain operates on the international scene more generally, Chapter 5 takes on the dilemma of regionalism versus globalism – is it possible or desirable to be a global power, inside or outside the EU, or is a regional destiny more practicable, even inevitable? That issue in turn leads in Chapter 6 to an assessment of Britain's principal bilateral relationships, with France and with the United States. France is a close analogue country for the UK and will face similar foreign policy issues in the future even as an EU member. As for the United States, it has had the paradoxical impact on Britain of both encouraging its EU membership and on occasions drawing it into global geopolitics in ways which have created tensions on the European front. The book ends with a consideration of whether a country which enjoyed opt-outs as a Member State finds itself in the position, now that it is facing life outside the Union, of seeking opt-ins to foreign and security policy cooperation, and whether that is a feasible or desirable outcome. Is Britain therefore indelibly ‘European’ from a geopolitical point of view? What are the interests that British governments, and the British people, seek to pursue through foreign policy?

In completing this project, many debts have been accumulated. I am first of all most grateful to Louise Knight, my editor at Polity, for her invitation to write the book and for her encouragement throughout. Her colleague Nekane Tanaka Galdos has also been both patient and professional in providing the support that every author needs. On the academic front I was fortunate in the immediate aftermath of my retirement from Cambridge University in being offered the post of the Wilson E. Schmidt Distinguished Chair of International Relations at the School of Advanced International Studies (SAIS), Johns Hopkins University, Bologna. In the Fall semester of 2017 I ran a European Research Seminar on the subject of this book with some excellent master's students, who contributed a great deal to my thinking by their sharp insights, enthusiasm and external perspectives on UK foreign policy. So my gratitude goes to: Vassilis Coutifaris, Francesco Diegoli, Malte Helligsøe, Caroline Mayr, Ginevra Poli, Juan Manuel Reyes, Umberto Speranza, Xiuqun Sun, Veerle Verhey and Lucie Webster. Also at SAIS, my colleagues Bart Drakulich, Erik Jones and Filippo Taddei have provided many stimulating ideas and discussion. Mark Gilbert took the time to read the historical part of the text and to make invaluable comments. I am also most grateful to SAIS Director Professor Michael Plummer for his welcome and assistance, and to Paolo Forlani, Gail Martin, Bernadette O'Toole and Barbara Wiza for indispensable and friendly administrative support.

Cambridge University's Department of Politics and International Studies (POLIS) is my other academic home. There my colleagues Chris Bickerton, Geoffrey Edwards, Mette Eilstrup-Sangiovanni, Brendan Simms, Julie Smith and Helen Thompson represent a formidable concentration of expertise in British and European politics on which I have been fortunate enough to draw. As a Fellow of Sidney Sussex College I also benefit from regular contact with James Mayall, whose judgement on international politics is always to be trusted. The College environment also means I can lean on the expertise of colleagues from other disciplines such as Kenneth Armstrong, professor of European Law and Eugenio Biagini, Professor of Modern and Contemporary History. I am grateful to the Master of Sidney Sussex, Richard Penty, for permission to spend the autumn at SAIS, and to Robbie Duschinsky, Mette Eilstrup-Sangiovanni, Bernhard Fulda, James Mayall and Rupert Stasch for kindly having covered for my supervising and interviewing duties during that term.

Lastly, I must thank a range of colleagues who have advised me on particular aspects of this work, encouraged me in various ways to proceed, or simply challenged my views. They might not always realize how helpful they have been, but I have not forgotten. So I acknowledge with sincere thanks my debts to: David Allen, Massimo Ambrosetti, Fraser Cameron, Charles Clarke, Marta Dassù, Renaud Dehousse, Helen Drake, Spyros Economides, Georgios Evangelopoulos, Andrew Geddes, Catherine Gegout, Charles Grant, Michel Kenny, Alan Knight, Christian Lequesne, Benjamin Martill, Maria Grazia Melchionni, Anand Menon, Anthony Milton, Tariq Modood, Robin Niblett, Tim Oliver, Alice Pannier, Mario and Annalisa Poli, Karen Smith, Michael Smith, Rick Stanwood, Eva Stolte, Nathalie Tocci, Uta Staiger, Richard Whitman and Jan Zielonka.

I am also indebted to various organizations for their invitations to speak during recent years on subjects related to the theme of this book, notably St Antony's College, Oxford, the London School of Economics (both its European Institute and its Diplomacy Commission), the University of Cologne, the Franco-British Council, the Greek Public Policy Forum in Chania, Crete, the Hay Literary Festival, the Istituto Affari Internazionali, Rome, the Libera Università Internazionale degli Studi Sociali, Guido Carli (LUISS), Rome, and the SAIS Alumni Association, Washington DC.

My fondest thanks, however, as always, go to my wife Maria McKay, who shows true devotion in reading everything I write and in putting up with the private agonizings of the author. We met as History students at Oxford at a time when Britain's attempt to join the EEC finally looked like succeeding. Our grown-up off-spring, Alice and Dominic, are fully European in their outlook. We only hope that the open Europe we benefited from will survive for them and for future generations.

Christopher Hill

12 June 2018