By a narrow majority, British voters have decided their country should leave the European Union (the so-called Brexit). One of the continent's largest economies, military power (including a nuclear capability), a global financial center, and a holder of a permanent seat on the UN Security Council is now preparing to negotiate its exit from the European project, on the grounds that good-neighborly relations and even productive cooperation with its neighbors does not require or justify the ceding of sovereign power and authority to a trans-national organization.
There is plenty of commentary on the economic and political effects of Brexit. I'd like to focus on the ethical implications. The Brexit matter focuses on two fundamental questions: 1) the nature of the political community and who are the "people" that exercise sovereignty (the demos) and 2) the nature of a state's contractual and treaty relationships with other states.
These issues are interrelated in Brexit. Originally, the European Communities were a series of compacts between states outlining mutual obligations. Over time, the European Union began to substitute the notion of itself as a political community made up of "Europeans" who owed each other rights and obligations on the basis of a shared European political identity. In other words, the EU was a state exercising power on behalf of a demos of Europeans—rather than being an association of states who had contracted with each other for mutual benefit and security. The Brexit vote indicates that of the 75 percent of Britons who turned out to vote, 52 percent see themselves as primarily British, subjects of a British queen and parliament to which they owe allegiance and who create a government that, in turn, they believe that they control and influence, rather than being Europeans under the care of the Commission in Brussels.
Thus, if Britain is the demos of the British, and not just one sub-unit of a larger Europe, then other Europeans who live in Britain are guests, admitted as part of a contractual arrangement that gives British the right to reside and work within the other "demoi" of Europe; and non-Europeans cannot be admitted to Britain on the basis of an order or diktat from Brussels, unless it is the sovereign will of the British to admit them.
The British have made their choice: a British demos that will contractually negotiate its exit from the EU and its future relationship with that organization. Will others in the EU follow?