The War was directed by 2 people:
Reasons For Entering War: As Germany refused to end the unrestricted submarine warfare, The U.S. officially declared war against Germany on on April 4, 1917. The prime motivation was that Germany attacked passenger and merchant ships. America replied with no mercy. Also, America and Great Britain were strong trading partners and America was not going to watch an Allie go down.
Alliances: America joined the Entente Powers as they all shared common enemies(France, Russian, British, Italy, France, Russia, and the United Kingdom) as a result of the triple entente.
Alliances: America joined the Entente Powers as they all shared common enemies(France, Russian, British, Italy, France, Russia, and the United Kingdom) as a result of the triple entente.