42 countries joined the league including countries like Britain and France. However, many
European countries were facing economic problems and had a weak military. Thus, countries were focusing on rebuilding their nation instead of working with other nations. Furthermore, the USA themselves did not join the league even though they played a major role in it having a large economy and the American Government refused to ratify the Treaty of Versailles, which led to the League of Nations. Another reason for the weakness of the league of nations would be their lack of credibility and authority. Due to their close association with the Treaty of Versailles, they soon built up the image of being the league for victorious nations. A large majority of the nations who were in the LON were on the side of the allies and peacekeeping measures were also inadequate.
For example, the league’s peacekeeping measures did not keep Japan and Italy from pursuing their expansionist policy in 1930. Another reason for the weakness of the league of nations would be their structural weaknesses. Various parts of the league did not work well together due to their conflicting ideas and probably trust issues, thus it was hard to take effective action as a league together.
Furthermore the secretariat was understaffed and disorganised. The system was also flawed since authorisation for any action required both a unanimous vote by the council and a two third majority vote in the assembly, thus actions will probably not be done since the members of the league did not want other nations to control their actions, therefore this voting system gave the members of the council the power of veto and it is extremely difficult to obtain unanimous consent for any decision or action