International audience The international and intertemporal comparisons of military expenditures are lacking precision. They depend on retained definitions concerning their content, they measure with difficulty the real rate of the inflation of products and military services and they suffer random fluctuations of the exchange rates. The statistics offered by SIPRI are currently used by econometricians, in spite of the existence of the « United Nations Standardized Instrument for Reporting Military Expenditures”, because without any verification process, the information delivered by the governments themselves clearly depends on the good will and mutual confidence of States. Today, the content of military expenditures changed and the used methods, even by the SIPRI, are lacking clarity and meaning.