This issue of the International Community Law Review brings together papers presented at a workshop organised in April 2013 on ‘Structural Challenges Facing International Organisations: Re-Assessing the League of Nations’.1The League of Nations is frequently used as a synonym for the failure to uphold world peace and security. Its more fruitful role in other areas of inter-national cooperation – health, culture, humanitarian, etc. – is now being rediscovered; but so far the rediscovery does not seem to have led to any gen-eral re-assessment of the ‘Great Experiment’ in world organisation (Robert Cecil). As Stephen Mathias observes in the opening statement of his keynote address . . . in contrast with the League, the UN has developed to become a strong, vibrant institution within whose framework today’s leaders seek solu-tions to political, social, environmental and legal matters at the top of the international agenda.” Seen in this light, the League of Nations seems to have yielded largely negative lessons, from which the United Nations would learn how to do matters differently. Membership, according to Mr. Mathias, is one such example: “[t]he drafters of the Covenant had, of course, already learned some key lessons with regard to membership from the failure of the League of Nations. In particular, the League struggled from the outset due to the absence of the United States.” Other challenges concerned the multitude of withdraw-als and the ensuing lack of cooperation.