This is a true statement, I just hope the damage done can be undone. We are stronger together than we are alone.
The US was never isolationist unless you ignore the existence of Native American Nations; it was brutally expansionist from day one. From the time of the Monroe Doctrine, US imperialism expanded even further, leaving the US “isolationist” in most of the 19th Century mainly only in regard to what happened outside the Western Hemisphere, and not even always there.
The expansion wasn't all of it; it was also an era of technological innovation in which the Americans were leaders (though Europe also produced a fair amount of innovation). But the expansionism had another advantage: while Europe was busy fighting a series of wars for control over the same territory, the US had a lot more freedom to devote to increasing production rather than destruction.
So the 19th century may not be an accurate model for the 21st. Isolationism was more feasible then because it was a large, self-sufficient nation. Today, capitalism has broken production down into finer and finer pieces and it's much harder for even a very large nation to compete against the combined strength of the rest of the world. If we don't collaborate, and others do, they'll gain a relative advantage that will slowly eat into our dominance. We can't simply conquer new territory because there isn't any, and even if we did, ownership of land isn't as important in a technological era.
World War I comes to mind as an instructive case against over-alliance. Likewise, in World War II, Switzerland remained famously unallied.
Not that I'm anti-alliances, but the common idea that allies are a key to survival isn't necessarily true.
It makes me wonder if some sort of international veto arrangement might be a good idea - unfortunately it seems that even if they did so they would be unlikely to listen "because this time is different".
Which is part of the reason why most democracies in history are representative democracies; they represent the interests of their constituents, not their constituents personal choices.
A representative should properly make the decision that, in their view, presents the best possible result for their constituency, not "what their constituents would choose if they were elected."
I fully believe in (representative) democracy, and with an extremely complicated issue like Brexit it needs dedicated politicians researching the issue and, ultimately, selling a solution to the public. I'm not deeply in tune with the parties in the U.K., but my general feeling has been that Labour has no fucking clue what to do, so all of the U.K. is just jumping into a yawning bottomless pit for no good reason.
let me show you exhibit A:
https://en.wikipedia.org/wiki/Western_betrayal
"allies" is a romantic concept that doesn't hold any water, only the return of investment forecast drives action and inaction.
> Nations with ardent and sincere allies
And, clearly though certainly teetering toward "no true scotsman," an ally who is only superficially allied (Germany and the USSR during the first half of WWII, or the Allies and USSR after the war) should not be considered an "ally," for all intents and purposes.
And I think it's clear in that specific example you gave how well selling out their allies worked for U.K. and France. If "greed" is your only motivation, eventually your greedy allies will sell you out as well. See, Prisoner's Dilemma or pretty much the entire field of ethics.