Defense One : "As representatives of twenty-eight NATO member nations convene in Wales for the 2014 NATO summit, there are a number of significant issues under discussion. One overriding concern, however, remains the proportional defense spending and overall military capability of the alliance. In order to provide context for this debate, we have visualized a publicly available dataset on military expenditures compiled by the Stockholm International Peace Research Institute (SIPRI). This graph traces, in constant U.S. 2011 dollars, the annual spending trends of each alliance member. To our knowledge, this represents the most comprehensive timeline of NATO’s 65-year evolution."