The availability of land, productivity of land and the temperature would probably dictate where to locate cities normaly, but assuming the overriding need is defence then one of the poles would be a good location. This is because a pole would be energetically more difficult to reach than any equatorial site. Any missile launched would be hindered by the rotational speed of the body it launched from in achieving a polar orbit as a polar orbit is at 90 degrees to that of an equatorial orbit.

That’s not to say that an attack could not be made, it certainly could, but a greater mass of payload warhead could be launched at an equatorial site than a polar site.

This is why the US use Vandenberg AFB for polar launches instead of Cape Canaveral AFB and the Russians use Plesetsk rather than Baikonur. Vandenberg and Plesetsk are much further north so a lot less equatorial spin velocity needs to be removed.

Assuming the overriding need is defence then one of the poles would be a good location. This is because a pole would be energetically more difficult to reach than any equatorial site. Any missile launched would be hindered by the rotational speed of the body it launched from in achieving a polar orbit as a polar orbit is at 90 degrees to that of an equatorial orbit.

That’s not to say that an attack could not be made, it certainly could, but a greater mass of payload warhead could be launched at an equatorial site than a polar site.

This is why the US use Vandenberg AFB for polar launches instead of Cape Canaveral AFB and the Russians use Plesetsk rather than Baikonur. Vandenberg and Plesetsk are much further north so a lot less equatorial spin velocity needs to be removed.

The availability of land, productivity of land and the temperature would probably dictate where to locate cities unless defence was the overriding concern.