in what sense were WWI and WWII British "own goals" ?
WWI was caused by every European power thinking they could benefit from a war, leading to powder keg that blew up from a completely inconsequential event. For the British one of the motivations was getting Germany's African colonies that were in the way of building the Cape to Cairo Railway, which ended up never being completed anyways.
WWII at least had a clear villain. But it was a villain that made every indication that he didn't actually want to fight Britain. Maybe that was a ruse and Hitler would have attacked Britain after securing the continent, maybe it wasn't and a British and German empire could have coexisted. We will never know. What we do know is that fighting WWII required Britain to bleed its colonies dry, followed by losing most of them in the years after the war
I'm not going so far as saying Britain shouldn't have fought the world wars. At least WWII had justification beyond what can be seen on map. However without participation in those two wars Britain would have had a shot at continuing to be a wealthy empire
I would however suggest that the two wars are basically the same war with just a big ceasefire in the middle, that's why I would treat them as the same mistake.
All that wealth and power wasted on turning Europe into a wasteland and sacrificing generations of young men.
In 1966 there was an industrial disaster where a school was submerged in coal waste and 116 children died. The coal company offered £50 per child as compensation. There was a national outcry that marks the change in attitude and the compensation was increased tenfold to £500 (quite a lot back then). Did we see this in Flint with the polluted water, or in Ohio when that train derailed with all the chemicals?
There's something about having absolutely everything in the world and then pissing it all away in an enormous own goal of world wars that is extremely humbling and I'd like to think that plays a key part in the British psyche and I think its for the better.
My grandparents were the war generation I knew, having lived through the blitz, and all they wanted was to sit in the garden and have a nice cup of tea. They didn't want to be the best or were looking externally for validation. Just a nice sit down and a chin wag and I think that's a positive way to be, as opposed to what I imagine was the driving force of the Imperial era in always wanting more and trying to prove how "great" our nation should be. We proved how great we are in two of the most destructive wars in the world's history where the entirity of Europe lost. We suck.