Howard was best known for expanding military history beyond the traditional campaigns and battles accounts to include wider discussions about the sociological significance of war. In his account of the Franco-Prussian War of 1870–71, Howard looked at how the Prussian and French armies reflected the social structure of the two nations. He was also a leading interpreter of the writings of the Prussian military thinker Carl von Clausewitz, including preparing the leading translation of "On War" with the American historian Peter Paret.