Europe had witnessed previously unimaginable horrors as a result of the First World War. With those atrocities fresh in mind at the Paris Peace Conference following the war, the League of Nations was seen as a vital necessity. Although ultimately not successful, it did serve as a precedent of sorts for the United Nations founding after WWII.
I think a League of Nations was very necessary. There had just been a World War and they did not want to have that again. The League of Nations would ensure other countries knew what was going on in the world and made sure there were open talks on peace resolutions.
The creation of the League of Nations even though it was not completely successful across the world did help somewhat. The creation of the League of Nations was something better than what we had ever seen before in the world. The creation eventually fell apart but, lead to the creation of the UN.
The League of Nations was a necessary creation at the end of World War I. The body's main goal was to preserve world peace, and it set up various organizations and agencies during its existence. After World War II, the United Nations took over the League and continued with its mission.
I don't think it was necessary to create the League of Nations because the world is soon going to be Legion of doom. The ever growing national debt is going to wipe out the world economy with due diligence and when this happens, it doesn't matter if we had a League of Nations.