Behind the United Kingdom's unexpected decision to leave the European Union was a resurgence in nationalism caused by a range of issues including economics, cultural change, and rising anti-EU sentiment. Economic factors include globalization and competition with foreign workers. The culture and immigration section discusses the backlash against post-materialist cosmopolitan values and demographic changes caused by immigration. The relationship between the United Kingdom and the European Union is analyzed using concepts discussed in Michael Hechter's Alien Rule (2013). In addition to these factors, we theorize that rising global tension and the interconnectedness of European countries were exploited by nationalist forces to strengthen the backlash against both the European Union and liberal cosmopolitan values in general.