It will perhaps not do to say that it is altogether a matter of sophistication.
Yet it may not exceed the premises to say that the particular choice, the concrete incidence, of this national attachment is in any given case a matter of sophistication, largely tempered with fortuity.

One is born into a given nationality--or, in case of dynastic allegiance, into service and devotion to a (fortuitously) given sovereign--or at least so it is commonly believed.

Still one can without blame, and without excessive shame, shift one's allegiance on occasion.

What is not countenanced among civilised men is to shift out of allegiance to any given nationality or dynasty without shifting into the like complication of gainless obligations somewhere else.

Such a shifting of national or dynastic base is not quite reputable, though it is also not precisely disreputable.