Alfred Thayer Mahan (September 27, 1840 – December 1, 1914) was a
United States Navy admiral,
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 those of the
United States,
Germany,
Japan and
Britain, ultimately causing a European naval arms race in the 1890s which culminated in the
First World War. His ideas still permeate the US Navy doctrine.