Final answer:
President Wilson faced opposition to his ideas among Allied nations and within the United States. Within the United States, there were groups that believed the provisions of the Treaty of Versailles were too harsh.
Step-by-step explanation:
President Wilson faced opposition to his ideas among Allied nations as well as within the United States. Within the United States, there were groups that believed the provisions of the Treaty of Versailles, which Wilson supported, were too harsh. Some ethnic groups were also dissatisfied with the national boundaries established by the treaty. Additionally, President Wilson faced opposition from conservatives in the Senate, such as Henry Cabot Lodge, who had concerns about the League of Nations and its provisions for joint economic and military action.