In 2015, a report was published regarding deepened defence cooperation between Sweden and Finland on all levels of war, from grand strategic to tactical level. The Swedish armed forces and the Finnish defence forces are similar in many ways, although there are some important differences. Sweden has participated in many operations in an international context, such as Libya, Afghanistan and Mali and the organisation is currently composed of professional soldiers. However, Finland’s contribution to international opera-tions is far less. As the Finnish defence forces still consists of a majority of conscripts and reservists, the contrast is obvious.The aim for this thesis is to study the conditions for the transnational cooperation regarding interoperability and Michael Codner’s strategic concepts. The result illustrates many differ-ences and similarities between the air forces, for instance differences in both nations’ force projection and combat capability. Furthermore, the result highlights some possible issues for an improved cooperation between the nations, such as Finland’s upcoming purchase of a new fighter aircraft.