Serious risk, and an ongoing one.

Tyranny is monopoly, and monopolies are synergistic with one another. The more monopolies we can make structurally impossiblev the less tyrants can hope to grasp.

(Enter Bitcoin) 

 With our modern lens it’s easy to forget, but traditionally people would go and cut the heads off people like this. This modern period where politicians get away with all sorts and never have to face the reality of themselves being sacks of flesh and bone is an anomaly that won’t last, it is perpetuated precisely because optionality doesn’t exist in the modern world.

Back then you didn’t need passports and visas to leave a tyrant like you do today. You didn’t have to traverse oceans. Didn’t have permissioned money that you couldn’t take with you. Didn’t have mass surveillance and Intelligence agencies infiltrating every nook and cranny where people might organise etc etc.

There is always a risk of an evil king, no doubt about it. Taking out one person is a lot easier than the hydra of a liberal democracy where no-one is accountable for anything though.

The key is to build wealth and prosperity through specialisation. Germany had this during its city state period (and it largely remained although bastardised thereafter), as did Italy before them. You can even see it in places in Asia albeit their culture is a bit different.

Allowing smaller regions to excel at certain things and having to compete is how the remaining principalities/city states have flourished whilst larger countries deal with non-stop internal and external conflict caused by trying to homogenise radically different groups into some incoherent mess of a society. https://i.nostr.build/zdYYz.jpg  

 A high rate of gun ownership among the population might deter an invader or at least drive up the cost significantly if you know that on every street behind every window could be a granny with a rifle.  

 This is a given for decentralisation to work. Relying on centralised security whether that is police or military leaves the people vulnerable. They don’t need to be well-trained militias, they just need to be well-armed enough that the MAD of any invader is sufficient deterrent that conflict is avoided in most scenarios.