Firstly, the absence of the USA. The League of Nations was thought up by the American president Woodrow Wilson it was one of his 14 points. He had come up with the idea, the League was in a sense his child, yet he was allowed no part in it. The American congress had refused to become members of The League and this caused all sorts of problems. America had the biggest trade industry and without them agreeing to economic sanctions they would be no use at all. That is what happened when Mussolini invaded Abyssinia, the League imposed sanctions but America continued to trade with Italy, this meant that the sanctions were useless. Another sanction that did not work without the help of the USA was military sanctions. Britain and France 's armies had both been weakened by the war and the rest of the league was relying on them to provide the troops. If America had been part of the League, they could have produced lots of troops for the army and the military sanctions would be more effective. Another thing is that the USA is a very powerful and rich country, the moral condemnation would have been more effective if the USA had been part of the League.
Secondly Britain and France put their own interests in front of the interests of the League. They made secret pacts with other countries behind the league 's back. In 1935 - during the crisis with Mussolini, the British and French Foreign Ministers, tried to make a pact with Mussolini. It was named the Hoare Laval pact and it aimed to give Mussolini two-thirds of Abyssinia. They were prepared to carry out the pact without even consulting with the League or with Abyssinia 's President Haile Selassie. Britain and France also made a pact with Italy know as the Stressa Pact, this formalised commitment to stay united with Italy against Germany. It was obvious that they were more interested in keeping on good terms with countries then bringing justice
Bibliography: : my own study notes + GCSE modern world history text book - second edition