SIPRI - Milex Database
The open-access Military Expenditures Database by SIPRI (Stockholm International Peace and Research Institute) provides latest data on defense expenditures worldwide. The current data, published in 2018, is calculated for the base year 2017 in US-Dollar. Basically, official documents of the respective governments, reports of the UN or NATO or secondary sources like magazines or newspapers are consulted for the annual data. Furthermore, SIPRI carries out its own surveys to complete the data. Since national defense expenditures can be transferred to non-scheduled budgets, they can be difficult to quantify. Hence, SIPRI sometimes reaches its limit with regard to the completeness of the data.