At the heart of the book “The Key to Nuclear Restraint” is the question why some nations have acquired nuclear weapons whereas others have not. The author Thomas Jonter, Director of Stockholm University Graduate School of International Studies and Professor of International Relations, is a well-known scholar in the field of nuclear history. He addresses the question of Swedish nuclear restraint against the backdrop of a general lack of research on cases of nuclear disarmament, claiming that most scholars focus on why proliferation of nuclear weapons occurred.
Throughout the book’s seven chapters the reader is informed about the 27 years of the Swedish nuclear weapons endeavor. It gives insight into the perspectives of various actors and institutions, which taken together form the full picture of those involved. The book connects to ongoing research on the Global Cold War, a field that is most prominently prescribed by Odd Arne Westad, while also engaging with the recent dialogues on nuclear issues to which other authors have already meaningfully contributed.
Jonter thoroughly analyzes Sweden’s nuclear weapons program, from the humble beginnings in 1945 until the phasing out of the research in the early 1970s. He covers the Swedish-American nuclear cooperation, the domestic political debate, the research activities of the atomic scientist community, the military stance towards a non-civilian program, as well as the public opinion vis-à-vis nuclear weapons. He locates the Swedish case in the context of the ensuing Cold War and the US-Soviet nuclear arms race.
Concerning the book’s methodological approach, Jonter has done a great job of drawing on Cold War history in an attempt to write a comprehensive history of the Swedish case. This necessarily highlights transnational entanglements such as technical cooperation and the engagement of Swedish actors in international disarmament initiatives.
It is vividly demonstrated how Swedish scientists were close to putting a bomb together in the 1960s, but for a variety of reasons the decision makers abandoned these plans and nuclear weapons research was terminated. Jonter shows how Sweden subsequently became one of the most vocal supporters of global nonproliferation of nuclear weapons and that its politicians were amongst the early signatories of the Nonproliferation Treaty in 1968.
Generally, Jonter interweaves an international dimension of the Swedish case with what happened inside the country itself, showing convincingly that domestic political decisions were not taken in a vacuum. Instead, he highlights the interrelations between Swedish and American decision makers and how they impacted on one another in a myriad of ways. His approach greatly benefitted from access to a well-documented nuclear weapons program in Swedish and American archives and recently declassified records. Nevertheless, it was not just an US-Swedish affair, because at certain points in time and to varying degrees of intensity, cooperation with French, Norwegian and British scientists also played a role.
The Swedes started their atomic research in 1945 with the aim to become self-sufficient regarding their nuclear energy supply. However, right from the beginning the program was designed in a way that it could accommodate the possible manufacture of nuclear weapons at a later stage. When the reactor fuel supply could not be met with domestic uranium, Swedish scientists looked for international support. At this point the US-Swedish nuclear cooperation began and the Americans were happy to supply the necessary fuel for Swedish light-water reactors, while general technological cooperation expanded with the US extending its influence over the Swedish nuclear energy sector.
It was through the enormous Swedish dependency on technological know-how that the US gained leverage also over their nuclear weapons program, a position used by the Americans to advocate for the termination of the latter. Jonter illuminates how the US lowered the price for reactor fuel to encourage Sweden to import fuel, because all the imported material was subject to US controls and could therefore not be used for the manufacture of Swedish nuclear weapons.
It is here that the author’s core argument comes to the fore, namely that the Swedish nuclear restraint can be traced back to their earlier choice to integrate the weapons project into the civilian nuclear energy program. This constellation resulted in an increased technological involvement of the Americans and led to their successful mission to discontinue Swedish nuclear weapons research. Additionally, the hesitant decision-making style of the political establishment in Sweden allowed for the formation of public opposition against nuclear weapons that in the 1960s persuaded politicians to terminate the non-civilian part of the atomic program. Jonter compellingly tells how central political figures in Sweden, such as Prime Minister Tage Erlander, a physicist by training, Foreign Minister Östen Undén, Supreme Commander Nils Swedlund and Inga Thorsson, a politician known for her strong anti-nuclear weapons stance, came to play decisive roles.
Owing to the variety of documents used, ranging from scientific documents to personal diaries of involved personalities, the author is able to show the trajectory of the public opinion, political circles and even within the military against nuclear weapons, and how over time key players changed their mind and reevaluated their position.
During the course of the book it is explained that the Swedish non-aligned position served as a point of reference for many politicians when they discussed nuclear weapons in order for the country to keep its neutrality in world politics. Furthermore, it is demonstrated how in the internal political debate a decision whether or not to manufacture nuclear weapons was for many years postponed. This was because the Prime Minister wanted to accommodate all the major Swedish parties without ruling out a decision in favor of nuclear weapons production in the future. However, due to this time-consuming wait-and-see approach, growing international opposition to nuclear proliferation ultimately impacted on the domestic debate.
While this book is written in an accessible language, its greatest strength may be the inclusion of different studies from nuclear scientists and assessments by the military leadership. This results in a clear and strong narrative, while at the same time the reader is guided to develop an understanding of the Swedish situation which allows to retrieve how Jonter arrived at his conclusions.
Concerning the scholarly debate on the Swedish case, the author himself has given a more detailed picture in an earlier article, while with regard to the analysis of the technical side of the nuclear weapons program, “The Key to Nuclear Restraint” draws also from another of Jonter’s publications. His most recent book however adds more dimensions to the Swedish case study, namely a detailed account of the US-Swedish relationship and a worthwhile examination of the domestic debate, including a rich description of the actors involved.
The only shortcoming of the book might be the lack of a more outspoken contribution to the debate on nuclear disarmament and nonproliferation. Besides two theoretical models against which the author positions and analyses the Swedish example, there is no real attempt to engage deeply with the scholarly debate.
That said, Jonter nonetheless positions himself by claiming that nonproliferation theories cannot in themselves sufficiently explain cases of nuclear restraint given the complexity of the issue and the dynamic interplay of actors with different interests.
In a nutshell, Jonter has thoroughly examined the Swedish case in a way that leaves no question unanswered and it is now up to other scholars to integrate his findings into more comparatively-oriented research. It was the author himself who in 2001 claimed that “a study of the entire issue of Swedish nuclear weapons would also embrace, in addition to the scientific-technical arena, the actions of the Swedish military, the game of domestic politics and an international level on which primarily the nuclear energy policy of USA is taken into account”. There can be no doubt that he has achieved this aim and his book is likely to become the authoritative account of the Swedish nuclear weapons program.
 Odd Arne Westad, The Global Cold War: Third World Interventions and the Making of our Times, Cambridge 2007.
 Anna-Mart Van Wyk, Sunset over Atomic Apartheid: US-South African nuclear relations, 1981-1993, in: Cold War History 10 (2010) 1, pp. 51-79; Rabinowitz, Or, Bargaining on Nuclear Test: Washington and its Cold War Deals, Oxford 2014.
 Thomas Jonter, Sweden and the Bomb: The Swedish Plans to Acquire Nuclear Weapons, 1945-1972, in: SKI Report: 01:33 (2001), pp. 1-84.
 Thomas Jonter, The Swedish Plans to Acquire Nuclear Weapons, 1945-1968: An Analysis of the Technical Preparations, in: Science & Global Security 18 (2010) 2, pp. 61-86.
 Ariel E. Levite, Never Say Never Again: Nuclear Reversal Revisited, in: International Security 27 (2002/03) 3, pp. 59-88; Scott D. Sagan, Why Do States Build Nuclear Weapons: Three Models in Search of a Bomb, in: International Security 21 (1996/97) 3, pp. 54-86.
 Thomas Jonter, Sweden and the Bomb, 2001, here p. 14.