whether that was the right choice will be seen in a 20 year timespan, given how soviet-like the direction EU has started taking looks like they might end up winners in this equation.
> given how soviet-like the direction EU has started taking looks
Then they should have left in twenty years. Britain has managed one of the more drastic peacetime reductions in wealth, influence and stability of any rich country post WWII.
The collapse of the USSR to Russia et al might count as a "rich" country doing worse. Can you name any others? Now I think about it, I suppose the loss of the British Empire itself might be one… after all, that was what got it excited to join the European project in the first place, though given national attitudes I'm sure the fact that the French boycotted it initially probably also helped sell the idea.