Without nation-states Covid-19, climate change, international cyberattacks, and other threats would go unchecked. In The World of States, John L. Campbell and John A. Hall challenge the view that nation-states have lost their relevance in the context of globalization and rising nationalism. The book traces how states evolved historically, how contemporary states differ from one another, and the interactions between them. States today confront a host of challenges, but two features make some states more effective than others: institutional arrangement and national identity. The second edition has been updated to discuss why the BRICS countries (with the exception of China) are no longer the rising powers they were once thought to be; the effects of Brexit on the European Union; the legacy of the Trump administration for US politics and hegemony; and how the coronavirus may upset the world of states going forward.