The Centre for the Study of Civil War at the International Peace Research Institute, Oslo (PRIO) and Uppsala Conflict Data Program (UCDP) at the Department of Peace and Conflict Research, Uppsala University, are the home for the Armed Conflict Dataset. The dataset allows users access to information on such variables as name of conflict, antagonists, whether/not there was third-party intervention, etc., for all global conflicts between 1946 and 2002. The website also has other data sources and illuminating charts and graphs, an example of which is reproduced below.
This chart shows the number of conflicts in various regions of the world over time.
Clouds, Clocks, and Sitting at Tables 
