In a paragraph, explain why President Wilson encountered opposition in the U.S. Senate in his efforts to ratify the Treaty of Versailles. Your response should discuss key terms such as League of Nations, Irreconcilables, Reservationists, isolationism, and interventionism.

President Wilson encountered opposition in the U.S. Senate in his efforts to ratify the Treaty of Versailles for a combination of reasons. One major factor was the Senate's concern about the provision for the League of Nations, an international organization aimed at maintaining peace and preventing future conflicts. Critics, known as Irreconcilables, opposed the League on the grounds that it infringed on American sovereignty and could draw the U.S. into foreign conflicts. Another group, called Reservationists, advocated for certain amendments or reservations to the treaty, primarily aimed at protecting American independence and sovereignty. These Reservationists sought to limit the League's authority over American foreign policy decisions. Furthermore, a strong sentiment of isolationism, stemming from a desire to avoid foreign entanglements, permeated public opinion and the Senate. Many senators feared that joining the League would make the U.S. obligated to intervene in international affairs, which went against this isolationist philosophy. Thus, while some senators were steadfast interventionists and supported the League, others criticized Wilson's treaty for its potential infringement on American autonomy and adherence to isolationist principles.