Theodore Roosevelt, Jr. (1858-1919) was an American statesman, politician, conservationist, naturalist, and writer who served as the 26th President of the United States from 1901-09. A sickly child, he overcame his health problems by adopting a strenuous lifestyle, and he integrated his exuberant personality, vast range of interests, and world-famous achievements into a 'cowboy' persona defined by robust masculinity. He was home-schooled before attending Harvard College, and later established a reputation as a learned historian with works such as The Naval War of 1812 (1882), and as a popular writer. He returned a war hero after leading the Rough Riders during the Spanish-American War, and was elected governor of New York in 1898. McKinley accepted him as his running mate in the 1900 election and Roosevelt's vigorous campaigning led to a landslide victory based on a platform of peace, prosperity and conservation. After McKinley's assassination in 1902 he assumed the presidency aged 42, and remains the youngest person to attain the role. At the outbreak of WWI Roosevelt strongly supported the Allies and demanded a harsher policy against Germany, especially regarding submarine warfare. He angrily denounced the foreign policy of President Wilson, calling it a failure regarding the atrocities in Belgium and the violations of American rights. In this book published in 1915 he lays out the moral and political case for coming to the aid of the nation's European allies, from the ethics of self-defence to the practicalties of preparing for war, calling for the US to strengthen its army and navy, and provide military training for all young men.