To deter is central for strategic thinking. Some of the more astute observations regarding the dynamics of deterrence were made during the Cold War by game theorists. This set the stage for how deterrence has come to be studied. A strong methodological element like the research on deterrence’s reliance on game theory requires examination in order to understand what sort of knowledge it actually yields. What sort of knowledge does one acquire when deterrence is viewed through game theoretic models? How do they inform us about the phenomenon of deterrence? To understand the nature of a phenomenon through models requires idealization, which in turn presupposes assumptions. This licentiate thesis investigates the type of knowledge we attain when approaching deterrence from a game theoretic perspective. The two articles presented address two separate but related issues. The first article reviews a debate regarding which deterrence model best capture the phenomena of deterrence, i.e. how models can be compared to one and other. The article presents a framework for comparing models and then appraises how these different deterrence models inform us about deterrence. The second article uses one of the more central deterrence models in order to evaluate how and to what extent the naval operation Atalanta managed to deter the Somali piracy.

Deterrence is the backbone of military strategy. Dissuading an opponent from taking a specific action by threat of violence is the definition of deterrence. From the outset of the Cold War there has been a strong link between the study of deterrence and game theoretic analysis. There are compelling epistemic reasons for studying deterrence as a game. By doing so, the strategic interaction between actors is placed at the centre of the analysis, mapping the possible outcomes and revealing the strategies available to the actors. Discussions about various models’ appropriateness and model comparison therefore play a central role in deterrence research; from underlying assumptions and deterrence representation to theory and evidence. This dissertation treats aspects of all of these topics. Article I, “Prospects of Deterrence – Deterrence Theory – Representation and Evidence”, analyses the relationship between model and theory and what happens to a deterrence theory when the rationality assumption is switched to a prospect theoretical utility function. Article II, “A Misfit Model – Bounded Rationality and Deterrence Representation”, defends and remodels Schelling’s idea of irrational threats for effective deterrence. Article III, “Comparable Deterrence – Target, Criteria and Purpose”, treats the issue of how one can compare game theoretic models with one another and proposes a meta-model for how this can be done. Article IV, “Deterring the Dauntless – Appraising the Effects of Naval Deterrence against the Somali Piracy”, estimates whether and to what extent Somali piracy was deterred by the naval intervention.

Avskräckning är ryggraden i militär strategi. Att avhålla en motståndare från engiven handling med hot om våld är definitionen av avskräckning. Redan frånkalla krigets början har det funnits en stark forskningstradition av att studeraavskräckning med hjälp av spelteori. Det finns också goda epistemiska skäl föratt studera avskräckning som spel. Genom att placera det strategiska samspelet icentrum av analysen, möjliga utfall åskådliggörs och spelarnas möjliga strategierblir synbara. Vetenskapliga diskussioner om olika vetenskapliga modellers lämplighetoch modelljämförelse spelar därför en viktig roll i forsningomavskräckning:från underliggande antaganden och representation av avskräckning till teori ochevidens. Artikel I analyserar mellan modell och teori samt vad som händer närrationalitetsantagandet byts ut mot ett prospektteoretiskt antagande. ArtikelII försvarar och ommodellerar Schellings idé om irrationella hot för effektiv avskräckning.Artikel III avhandlar hur olika avskräckningsmodeller kan jämförasmed varandra och föreslår en metamodell. Artikel IV skattar om och i vilkenutsträckning de somaliska piraterna blev avskräckta av de marina operationerna.137