Earlier quoted context omitted.
Choosing Scotland over the more usual U.K. or British, is peculiar. It's like saying a Russian aircraft violated Alaskan airspace rather than US airspace. This choice is possibly indicative of other subsurface politics.
Scotland is the UK . Scotland's airspace is managed by the UK central government. This is like saying "flying over Maine, rather than over the more typical USA, is suggestive of subsurface politics".
Scotland is a country in the UK (as are England, Wales, and Northern Ireland.)
Its also a country with a fairly strong independence movement and which is frequently at odds with the central government on important policy issues.