jun 28, 1919 - Treaty of Versailles
President Wilson demonstrated his intentions of moral diplomacy through his proposal of 'Wilson's fourteen points'. Moral diplomacy is the system in which support is given only to countries whose moral beliefs are analogous to that of the nation. He ended his neutrality in WWI due to disagreeing with the morals behind the German's "U-boat" warfare and therefore tailoring US foreign policy relative to this.
Added to timeline:
20th century US foreign policy