The real reason for Britain withdrawing from the EU is, in the EU’s oft-repeated — and never denied — its intention to become an “ever-closer union”. This is going against the historical trend.
The plain fact of the matter is that the large empires of civilization — 50 or so in Eurasia and half-a dozen in Central America — have lasted for decreasing numbers of years before breaking up. This trend has much to do with the increasing numbers of specializations within each empire and the increasing difficulty of its centralised power base in being able to cope with them.
Thus, in the last 8,000 years we have seen the formation, and then the break-up of civilizations into smaller regions, and, more recently — in about the last 300 years — the formation of what we presently call the nation-state. Any empires that happened to have formed during that period — the British, Russian and Japanese — didn’t last long,
The only empire still existing — the Chinese — will inevitably go the same way one supposes, but what’s of current concern is the attempt by EU bureaucrats in Brussels — and those politicians they give favours to — to actually form yet another empire. But it’s rowing against the tide.
The EU will probably break up before the Chinese. The latter at least has a common written language and a highly deferential culture to hold it together. The EU has neither of those and, in its most recent grab for more power as its expansion has taken on board at least half-a-dozen eastern European countries that are already more troublesome than Britain has ever been. They’ll be more so when they discover that, after the initial uplifts when they join, the standard of living of the EU as a whole is now actually declining.