United Service Institution of India (USI) is a national security and defence services think tank. It based in New Delhi, India. It describes its aim as the "furtherance of interest and knowledge in the art, science and literature of the defence services". USI operates centres for research in various areas of national security. The USI Journal, published quarterly since 1872, is the oldest defence journal in Asia. It also publishes a number of monographs based on research and study by its members. More information on the Wikipedia page [1].