I said small country in the original post, because while I imagine the US has similar levels of dynastic cliquey stuff going on, it's a colossal nation, so it doesn't hurt so much.

In the UK, I think Eton is more a symptom than a cause. The problem is, London is a world-class city that concentrates the entire political and financial establishment. It's also a city with very obvious parallel worlds, where if you move in certain circles, you meet the same people, so while it is a massive city, it sometimes feels quite small.

To me, the worst part is not that both Johnson and Cameron went to the same school, the same university, or even the same exclusive dining club - the bad bit is that because any given person with political, social or economic power in the UK is so closely connected with any other, there's a real incentive not to rock the boat. You get an enormous amount of cohesion, because if you go around making enemies, you're ultimately making things awkward for a lot of your friends and acquaintances.

On top of that, the fact most people in this world have similar backgrounds makes a lot of them 'on the same page' by default.