Final answer:
The American rejection significantly undermined the League of Nations, depriving it of crucial support necessary for taking action on global issues.
Step-by-step explanation:
The League of Nations was established with the vision of promoting peace and preventing conflicts worldwide. However, the absence of the United States severely weakened its effectiveness. The US, with its economic power and diplomatic influence, was crucial for the League's ability to enforce decisions and maintain stability. Without the US as a member, the League lacked the necessary authority and resources to address major international conflicts and disputes effectively.
Moreover, the absence of the US diminished global confidence in the League, as it was perceived as a predominantly Western European organization without the representation and support of a significant global power. This rejection hindered the League's ability to implement sanctions or enforce resolutions, ultimately limiting its capacity to prevent escalating tensions and conflicts.
Thus, the American rejection significantly hampered the League of Nations' ability to fulfill its intended role as a global peacemaker and arbiter.