According to John Mearsheimer, the United States entered the First World War because the Wilson administration believed the Triple Entente was on the verge of defeat. As a result, he claims, the Americans entered the war to prevent Germany from becoming a regional hegemon in Europe. A careful and targeted examination of the relevant primary sources, however, demonstrates that Washington was largely unaware of the plight of the Allied powers in the spring of 1917; therefore, the argument that the United States was acting as an offshore balancer at this time is unconvincing. This article shows that unit-level factors and statecraft can play a larger role in international relations than structural realist theory allows and makes an empirical contribution to the World War I literature by demonstrating that balance of power considerations were not a major factor in the Wilson administration's decision for war.