The situation with Brexit is somewhat similar to what took place under similar aspects between Uranus, Neptune and Pluto about 493 years (one Neptune/Pluto cycle) ago. In the 1520s under aspects similar to the period 2000-16, about half of Europe, including Spain, was unified as the Holy Roman Empire. By 1522, this superpower also conquered most of Central America and the Philippines. However, in the period 1524-29, under the planetary aspects roughly corresponding to the period 2016-21, the Empire began to crumble. The process of disintegration lasted almost three centuries, but very few remember now that this empire ever existed. This is how it was with all superpowers, from the Assyrian Empire of antiquity to the European Union of today; once they begin to shrink, the process is irreversible.
The European Union seems to have inherited the fate of the Holy Roman Empire. After a rapid initial expansion in the 1990s, the process of European integration into a super state has stopped. In recent years, the EU was not able or willing to accept Turkey, Georgia, Ukraine or Moldova, almost lost Greece, and now Brexit. So, the next 4-5 years will decide the fate of this union. If Brexit indeed takes place for real; and/or other nations also leave the union, the EU will continue to disintegrate. However, if Britain remains in the union, other nations will join it as well; and a truly united Europe will eventually emerge. In a few decades, it may include even Russia or at least the European part of Russia.