As Secretary of State for the Navy (1897–1916) his first Navy Bill in 1898 began the expansion of the German navy and led to the naval race with Britain. In 1907 he began a large programme of Dreadnought‐class battleship construction. During World War I he made full use of submarines, but following the sinking of the Lusitania (1915), unrestricted submarine warfare was temporarily abandoned. The policy was resumed in 1917, resulting in US entry into the war.