NO historian believes that history repeats itself. Yet, between different ages there are frequently striking analogies and resemblances. It is prob lems that repeat themselves, not the conditions which determine their solution. One of these problems, recurrent in European annals, is that of the maintenance of a certain balance of power among the various nations as essential to their freedom, the maintenance of a situation to which they are accustomed and which-they have found tolerable, a change in which would be prejudicial or dangerous to their peace and safety. Several times in modern history this balance has been threatened and Europe has purchased immunity from servitude by freely giving its life blood that life might remain and might be worth living.