High Quality Content by WIKIPEDIA articles! Alfred Thayer Mahan (September 27, 1840 – December 1, 1914) was a United States Navy flag officer, geostrategist, and historian, who has been called "the most important American strategist of the nineteenth century." His concept of "sea power" was based on the idea that countries with greater naval power will have greater worldwide impact; it was most famously presented in The Influence of Sea Power Upon History, 1660–1783 (1890). The concept had an enormous influence in shaping the strategic thought of navies across the world, especially in the United States, Germany, Japan and Britain, ultimately causing the World War I naval arms race. His ideas still permeate the U.S. Navy Doctrine.