In the aftermaths of the Napoleonic Wars and the two world wars, the Western great powers made repeated efforts to build a world order that would establish peace and protect their interests, organized around various types of international bodies. Mazower is interested in why they did this and why, in particular, the United Kingdom and the United States invested so much “time and political capital” in building international institutions. If the book has a general thesis, it is that the global institutions created in the name of liberal institutionalism have really been tools used by great powers to expand their influence, protect their sovereignty, and keep other countries in check. The most interesting chapter focuses on the way mid-nineteenth-century scientific visions of the world as a system, along with the new professions of statistics, engineering, and geography, spurred the creation of new forms of international organization and cooperation. Mazower is clearly fluent in the history he relates, but he fails to engage the vast literature of international relations scholarship that explores this topic, missing an opportunity to develop a more formidable and novel argument.