An explosion destroyed a section of railwaytrack near the city of Mukden
Japanese who owned the railway blamed the Chinese for the incident and used the opportunity to invade Manchuria
Japan conquered Manchuria in 1932, The League objected but could do little in response (they had no army) When the League supported Chinas sovereignty Japan left the League in March 1933 - Manchurian Crisis
This demonstrated the Leagues weakness and the futility of agreements of peace, non-aggression and disarmament in the face of a power determined to march forward
Abyssinian Crisis
Italy invaded Abyssinia in 1935, although the League officially condemned the Italians, Britain and France were caught making a secretagreement to give Abyssinia to Italy
This demonstrated the weaknesses in collectivesecurity and that aggressive actions could take place without severe consequences. This encouraged Hitler.