The determination of military expenditures has been the subject of a great deal of economic literature. It is undeniable that GDP and national wealth influence the level of the military budget. On this basis, economists have developed arms race models, incorporating grievances between states and the effects of inertia spending. However, many other factors can be highlighted, such as the evolution of threats, the birth of new weapons, the will of power of a state, alliances, the existence of a national arms industry, the rise of military research and development, the budget of the state or the taking into account of the values of the future.