The Nordic countries are facing similar threats and the countries share many security policy and interests, Nordic co-operation provides an increased threshold effect and reduces the risk of incidents in and around our vicinity. The research problem for this study is whether a Nordic defense cooperation between Sweden and Denmark has the prerequisites required for successful defense cooperation. The purpose of this study is to investigate whether Sweden and Denmark have the conditions required to have a successful defense co-operation based on Tomas Valasek's success factors for successful defense cooperation. The conclusions that can be drawn after this study is completed are first and foremost that a deeper Nordic defense cooperation between Sweden and Denmark has all the success factors that Tomas Valasek says create good conditions for a successful in-depth defense cooperation. We can see that the results of this study after analysis have been carried out based on Valasek's factors show that Sweden and Denmark have both met all the factors in the same way and have similar results where this has been presented.