The League of Nations faced several critical issues that contributed to its ultimate failure:

1. Limited Membership and Lack of Representation:
• The League of Nations had restricted membership, which meant it lacked the legitimacy of being a truly representative global organization. The absence of major world powers like the USA, USSR, and Germany at its inception weakened its standing as a world body.
2. Financial Constraints:
• The limited membership also led to financial difficulties for the League, hindering its ability to carry out its work effectively.
3. Non-Involvement of Major Powers:
• The absence of the three major world powers - USA, USSR, and Germany - at the outset of the League's formation further undermined its authority and effectiveness. Germany was only admitted in 1926, and the USSR gained membership in 1934.
4. US Policy of Isolationism:
• The United States, a key global player, never joined the League of Nations, and it also did not ratify the peace treaties. This was largely due to a shift in public sentiment away from Woodrow Wilson's vision and towards a policy of isolationism. Many Americans viewed the League as a potential threat to US sovereignty and freedom.
5. Withdrawal of Member Nations:
• Japan, and later Germany, withdrew from the League of Nations, further weakening its influence and effectiveness.
6. Ineffectiveness in Dispute Resolution:
• The League struggled to enforce its decisions, especially in cases where the verdict went against a major power. Aggressive regimes like those in Japan, Italy, and Germany openly defied the League's authority.
7. Impact of the Economic Crisis of 1929:
• The global economic crisis of 1929 played a significant role in the League's failure. It exacerbated financial difficulties and led major powers to prioritize their own economic interests over collective security efforts.
8. Role of the Conference of Ambassadors:
• The continued existence of the Conference of Ambassadors, even after the establishment of the League, undermined the League's authority, as decisions made by the Conference sometimes overruled those of the League.
9. Weaknesses in the League Covenant:
• The League Covenant itself had certain weaknesses that hindered its ability to provide genuine collective security.

In summary, the League of Nations faced a combination of structural, political, and economic challenges that ultimately contributed to its inability to prevent the outbreak of World War II. Despite its noble aims, the League fell short in achieving its mission of maintaining global peace and security.

Impact of the failure of the League of Nations:

1. Loss of Faith in International Institutions: The League's inability to effectively respond to acts of aggression eroded the trust and confidence that smaller states had in international organizations. They began to doubt the League's capacity to maintain global peace and security.
2. Encouragement of Aggressive Regimes: The League's failures, especially in addressing actions by aggressive regimes, emboldened leaders of such regimes. Adolf Hitler, in particular, gained confidence from the League's inability to prevent acts of aggression. This encouraged him to challenge the Treaty of Versailles, leading to further destabilization in Europe.
3. Onset of World War II: The League's inability to prevent international conflicts ultimately contributed to the outbreak of World War II. The League's failure to contain acts of aggression by fascist regimes and other aggressive powers meant that military conflicts escalated, ultimately resulting in the widespread and devastating conflict of World War II.

In summary, the League's ineffectiveness in maintaining global peace and security not only undermined trust in international institutions but also allowed aggressive regimes to pursue their expansionist policies with impunity, leading to the catastrophic consequences of World War II.