International organizations like the United Nations, the International Monetary Fund, or the European Union are a defining feature of contemporary world politics. In recent years, they have also become heavily contested. In this book, we examine how the motives for praising or criticizing international organizations have changed over the past 50 years. Looking at five organizations in depth, we observe two major trends. First, international organizations are
increasingly asked to demonstrate not only what they do for their member states, but also for the people living in these states. Second, international organizations are not only evaluated based on what they
accomplish, but also based on how they arrive at decisions, manage themselves, or coordinate with other organizations in the field. In sum, the list of expectations international organizations need to fulfil to count as 'legitimate' has expanded over time. This makes the legitimation of the UN, the EU, and its peers more challenging today.