The American belief at the beginning of the war was that it would be short conflict reminiscent of the fight between Germany and France in 1870(Zieger, 9). At the time both the Allies and the Central Powers, along with Americans, miscalculated the impact the involvement of American forces could have for either side. The U.S. Navy was expanded and upgraded during the presidency of Theodore Roosevelt but the Army was still a minimal force.
To keep with the "true neutrality" the United States initially refused to aid either side with supplies or economic assistance. Once the battles became entrenched and a "war of attrition" began, the European nations continued to look toward the United States for aid. As American financial institutions and exporters sought guidance from Wilson's administration they received a different answer: "short term loans and credits by American financial institutions to belligerents in connection with trade were acceptable" (Zieger, 11). Americans could not over look the potential economic boost that could be achieved by supplying the European nations with food, supplies and weapons orders being requested.
Both sides accepted the United States' aid but they also sought to cut-off each other's supply chain. While the Allies barricaded Germany's ports with the British Navy, Germany began
References: Zieger, Robert H. (2000). America 's Great War: World War I and the American Experience. Lanham, MD: Rowman & Littlefield Publishers Inc. Davidson, J. (Ed.). (2002). Nation of nations: A concise narrative of the American republic. (3rd ed., Vol. 2). New York: McGraw-Hill