First published in 2012, Borders: A Very Short Introduction began with the premise that "we live in a very bordered world." The intervening decade has witnessed a flurry of events and developments that continue to highlight the centrality of borders in contemporary domestic and international affairs, as well as the interstices between the two, including sudden surges in migrant and refugees flows; renewed emphasis on traditional border security and wall construction; growing tensions concerning maritime sovereignty; rapid advances in cybersecurity, surveillance, and biometrics; expanded detention and deportation infrastructures; proliferation of transborder organizations; revived populist and nationalist sentiments; and protectionist and integrationist trade practices, to name some prominent examples from recent headlines. This revised edition accounts for recent developments including Brexit, the 2015 migration crisis across Europe, efforts to build a border wall between the US and Mexico, growing isolationist and nativist sentiments, demands for indigenous homelands, transnational protest movements, Russian cross-border incursions, and insurgencies and rebellions across much of North Africa and Southwest Asia.