European history may be about to go into reverse.

If Britain votes to leave the European Union, it will likely start a process of fragmentation of the political and security structures on which the post-World War II and post-Cold War European order was built.

Even if the British step back from the brink Thursday, the bruising legacy of the debate, the growing trend of national referendums on EU issues and the backlash against globalization and internationalized elites on both sides of the Atlantic will not fade away any time soon.