Ask Lemmy

You might have got your size a bit off maybe?

You're describing an island which would be the second largest island on earth after Greenland, and bigger than most of Europe but with a population similar to Canada's.

Your first problem would be population and target density.

Some countries, especially European ones would be almost impossible to conquer. Population density is simply too great and most European countries have dozens and dozens of large cities.

That means valuable military and strategic targets are not only spread across the entire country, but they can also be easily defended.

However in a scenario you are describing, most countries of that geographic size tend to have one or two extremely large cities in coastal areas, and the rest is generally barren and uninhabited. So you're looking at a situation similar to that of Australia, 30 million people concentrated in just 5 or 6 large cities with nothing in between. Very easy to invade, very easy to get a foothold.

Your first priority is to spread out your population and any potential targets. Gone are the mega cities, 20 to 30 cities all over the country with a population of over a million.

You are now able to spread out your strategic resources and ensure they are heavily defended.

You also need to invest heavily in air defence, and keep it mobile and hidden. Consider storing caches of handheld aa and at weaponry.

Invest heavily in your airforce, antiship warfare AND your navy, particularly submarines and small unmanned naval drones packed with explosives. You're an island nation. If your attacker can't get to your coastline they cant land troops.

If your attacker is America, you only need to sink a couple of carriers and they'll give up.

Your land based forces, must be mobile and able to act independently. Any military in the top 10 will concentrate on degrading military targets first. You need to be able to quickly disperse your forces and ensure they can resupply from dispersed supply depots - under cities will be best.