What weaknesses made the league of nations an ineffective force for peace in the 1920s and 1930s?

The League of Nations was to be an international association whose goal would be to keep peace among nations, but Germany and Russia were excluded. After the Great Depression, most of the country had economic problems. Japan, Italy, and Germany started to plan to invade other countries for the goods and more living space: Japan invaded Manchuria and China, encouraged Italy invaded Ethiopia and Albania; in the case of Hitler, he invaded Rhineland, Austria, Sudetenland, Czechoslovakia, and Poland, respectively.

Japan used to sign Kellogg-Briand Pact which not to engage in war, but they invaded Manchuria for the goods, materials, and more living space. It is the direct challenge to the League of Nations because Japan was a part of them before the invasion, and the League of Nations did not do anything. The failure to stop Japan encouraged Italy to invade Ethiopia for the goods. When Italy was invading Ethiopia, the Ethiopian leader, Haile Selassie was asking for help from the League of Nations, but the League of Nations did nothing again. The League of Nations did not want to get involved in the war, and they did not give any punishment to the aggressors, it caused Germany invade more countries indirectly.