If you want security the concept of the mega city needs to be abandoned.

In a decentralized country you don’t care about terrorism attacks, nuclear bombs, coups, revolutions, drones and what not.

Mega cities are a lot more efficient and I think most people would rather live in one than a small town.

And they're actually easier to protect because you can build all your bunkers, barracks, drone bays and ABMs close together. The attack surface is a lot smaller. In less urban countries you have to decide what needs protection, and if you guess wrong more people will end up dead.

We should be decentralized in terms of power, not geographic distance. A city where everyone has a gun and military training is much harder to attack than 100 villages with the same total population. The important thing is making sure that even if the city falls theres a plan to avoid civilian casualties, and the rest of the country is independent enough to work without it.

Trading off efficiency for security is not wise unless you are in war. The same applies to supply chains.

Not just for security - generally speaking if you have high speed rail infrastructure connected to a good and fast public transport grid, there's genuinely no reason to build a huge city.

High density housing is very slow to traverse and getting from point A to B in a big city might take more time than getting on a train that takes you to another city 200km away in 30 min. In a traffic jam, you'll be lucky to do 5km in the same time.

“Encircling the cities from the countryside" (农村包围城市) is the foundational military and geopolitical strategy developed by Mao Zedong during the Cultural Revolution and Great Leap forward, building a distributed self sustaining (military) industrial complex. It was very hard to build and maintain. Altho a lot moved to the coastal areas again, there are constant oscillations and negations between the rich costal cities and the hinterland (data centers, taobao villages)

Writing from London I'm not planning on abandoning. It might be nice to have a country place too in case Russia nukes.

There's a tradeoff there, because a very distributed society will also be able to resist disruption and control from a central state.

There was far less risk to cities before social media algorithms sent the world fucking mad and helped get a total psychopath into the oval office and tore apart the world order and globalism.

But yeah, it's looking like state sponsored terrorism is back on the menu for those in cities, once everyone moves to the countries, small communities can be targeted by random drone attacks by Russians or something. Will be great.