Answer: President Theodore Roosevelt believed that the United States needed a war during the late 1800s to early 1900s for several reasons. Firstly, he believed that the country had become complacent and needed a boost of patriotism and national pride to unify its citizens. Secondly, Roosevelt believed that the country needed to assert its military strength on the world stage, especially in light of the country's rapidly expanding economy and growing industrial might. He believed that a successful war would demonstrate the country's military prowess and solidify its place as a world power. Additionally, Roosevelt felt that a war would help to settle disputes between the country and other nations, thereby ensuring peace and stability. Overall, Roosevelt believed that a war was necessary to protect American interests and to solidify its position as a dominant world power.