The United States' entry into the Great War marked the abandonment of the traditional American policy of isolation and independence of world politics. Not at the close of the Civil War, not as the result of the Spanish War, but in the Interwar period did the United States become a part of the international system. With this global reorganization from the Great War, there were those in the American populace that advocated an activist role in international politics and international affairs by the United States. Activities that were initiated did not fall into political-military traps and, instead, focused on economic-ideological approaches that would increase the American Empire and general worldwide stability. Following the prior path, a precursor to the United Nations and a league to enforce peace, the League of Nations, was proposed by Woodrow Wilson. This was rejected by the American Government in favor of more economic-ideological approaches and the United States did not join the League. Additionally, there were even proposals of extending the Monroe Doctrine to Great Britain put forth to prevent a second conflagration on the European theater. Ultimately, the United States' proposals and actions did not stop the factors of European nationalism spawned by the previous war, the repercussions of Germany's defeat, and the failures of the Treaty of Versailles from plunging the globe into a Second World War.