ABSTRACT
The United States declared war on Germany on 6 April 1917. The immediate cause was the German resumption of unrestricted submarine warfare early in 1917. The Germans had expected this reaction but thought the U-boats would starve Britain into surrender within a few months and thus render American intervention ineffective. This was a miscalculation: Britain survived the submarine threat, and United States participation was an important factor in clinching the issue in 1918. The most famous case of a prosecution under the wartime acts was that of the Socialist Party's leader Eugene V. Debs, four times candidate for the United States presidency. But there was no reference to the war being unjust or predatory, no criticism of the United States government's decision to go to war, or of their conduct of the war – nothing that could be construed as apt to 'interfere with the operation or success' of the armed forces.
