This is a no brainer. A country leaves the largest trading bloc, and gives up it's contingent political influence, and drops 2 places in the World GDP rankings has not enhanced it's standing. Nationalism is an ugly facade, even if Britain is not unique in succumbing to it. Economically and politically inclusion is a far more positive and generally beneficial perspective to take.
This vote betrays the fact that Britain has never really understood the benefit or purpose of the EU, which is fundamentally and primarily to promote peace in Europe. The EU is predicated on the idea that with common and shared prosperity and dependency a war between European nations is much likely - an idea lent strong support by the absence of major conflict between European nations.
It is important to recognise that the EU is not perfect, but the justifications for BREXIT are mostly false or bogus. It is not undemocratic - the powers of the Commission to draft legislation are very similar to democratic processes in other nations, and are pragmatic given the need to ensure legislation can operate in any one of 27 nations. Nothing happens without approval by the European Parliament, and/or the council of ministers - if anything it is excessively ponderous in it's actions. Britain has actually objected to very little legislation - there can be no question any British citizen would have opposed far more UK legislation than EU. So the sovereignty argument, whilst ultimately sustainable is overstated. It is like insisting on driving a car when you have a chauffeur who drives very safely, if a bit slowly, and it is more comfortable in the back - you can, but why not relax?
It is not impossible that by some quirk of fate BREXIT could work out well for Britain, but the odds don't favour this outcome. This is underlined by the arrival of Trump in the White House - unreliable and inconsistent, it is more or less inconceivable the UK will "get a trade deal", and given that UK:US trade is worth about 1/20th of UK:EU trade, who cares, but more importantly, aligned with Europe the UK is far more secure.
BREXIT is a tragic mistake that Political scientists, economists and academics will pore over for decades. It reflects perhaps the final gasp of British exceptionalism, or is it the last hurrah of the British empire and as such will mark Britain's return to the ignominy and irrelevance that characterised the early post war years till, ironically Britain joined the EU. Empires do have a habit of not realising they are dead until long after the last rites.
I hope I am wrong.
I think there are but a few people who would say that the outlook for Britain's position in the world got better from Brexit.
In the 21st century, if you're a small country like Britain you have to latch onto either the US, the EU or China or Russia. Those are the powers you can bandwagon along with. Right now the UK has two of those four as close friends: the EU and the US. I think that the US and UK are still going to be close friends, no matter who is in power in the White House or Downing Street. But any sort of weakening of ties between the UK and the EU is likely to be bad for Britain's standing in the world.
It's also questionable whether or not the trade ties can be resolved. If the single market is taken off the table, every economist agrees it would be bad for the UK. And this is the rub: how do you deliver on the mandate which a lot of people voted on, based on immigration? I cannot imagine a world in which Angela Merkel is able to sell the idea of a points-based system for any EU citizen wanting to come to the UK, but where British workers will be able to work wherever they like in the EU. Its never going to happen.
"In order to participate in a single market you have to sell products that abide by EU rules. And that's not what the Brexiteers voted for."
Or rather its not going to happen unless a soft Brexit occurs, where the only changes would be to take away the UK's voting power but still to allow it to be part of a single market also to allow them to have a say in immigration. That would be a problem: it would mean accepting regulation without representation with no real change to the stuff that people were upset about in the first place. So the 'Take back Britain' idea is one that basically hinges on economic downturn. In order to participate in a single market you have to sell products that abide by EU rules. And that's not what the Brexiteers voted for.