But fair would be to evaluate the success ratio of option 2 as well: look up "league of nations", "concert of Europe" and there have been several organizations

But fair would be to evaluate the success ratio of option 2 as well: look up "league of nations", "concert of Europe" and there have been several organizations before that ... They all are definitely structures founded to prevent war ... and now the consensus is mostly that they caused WW2 (they were the ones organizing the "Treaty of Versailles").