Governing the World: the History of an Idea by Mark Mazower
This was a review of ideas for world governance. It touched on the Concert of Europe, socialism/communism, the League of Nations, the United Nations, international banking/trade and international law.
I found the discussion of US relations to the UN very interesting. Also the idea that institutions such as the World Bank and the IMF were useful to allow US ideas to be imposed but without appearing to originate from the US was also interesting.