multitool
Pharaoh
I understand what you say, and there are undoubtedly people in this country who still hark back to those days, particularly those of the older generations and some of the Yaxley-Lennon tendency, but that number is diminishing rapidly and is probably a small minority, except in the Tories and Reform parties.
Yes, we did build our wealth on our military strength and exploitation, and need to remember that rather than look at the past through rose tinted glasses, but that does not explain why other European countries like Spain, The Netherlands, France, Germany etc. who did something similar all remain in and support the EU. Why have they moved on and we haven’t? I put that down as much to our island status and historical distrust of ‘that lot over the channel’ as yearning for the lost days of our imperial power. Brexit was a mistake and as much about isolationism, mistrust and dissatisfaction as the lost days of grandeur, exploited by a very cynical Leave campaign.
I agree with all of that with the caveat that all of the EU countries you list have slightly different imperial pasts (none of them were as big as the British empire) and post imperial pasts. All of those countries were heavily affected by WW2 which was essentially what drove the foundation of the EEC. But equally they all have nationalist movements.
I would make two points. The UK had its populist movement early (see the current rise of the nationalist right in Germany, Netherlands and Italy). Whilst there was talk of Frexit etc this had been killed stone dead by the failed example we have set. Note how the Brexiteers were all crowing that the rest of Europe would follow...but none of them are doing that now.