The statement that best analyzes the political role of the U.S. in World War I is:
Without U.S. manpower and supplies, the Allies would not have won the war, so the Allies thought it was important to use American ideas.
This statement acknowledges the significant contribution of the U.S. in terms of military and material support, which was crucial for the Allies' success in the war. It also implies that this contribution gave the U.S. a degree of influence in shaping post-war ideas and negotiations, despite any prior isolationist policies.