The purpose of this article is to assess the Stockholm International Peace Research Institute's (SIPRI) updated military expenditure data for Greece and Turkey. Testing for data reliability involves two stages. First, for 1949-2014, the time pattern of Turkish military expenditure is explored by comparing national military budget data with the updated SIPRI data. Second, the new data for 1980-2001 are used to replicate an earlier study on possible action-reaction military spending behavior between Greece and Turkey. The findings still hold when the analysis is based on SIPRI's updated data.