As we know, Martin van Creveld has demonstrated that immigration is simply another form of war, and an invasion is an invasion regardless of whether it is a peaceful, unarmed, and disorganized one that is welcomed by a governing elite or an armed and organized one that is resisted by the governing elite.
But one of the lessons demonstrated by Sir Charles Oman in his The Art of War in the Middle Ages is the way in which immigration and the reliance upon foreign troops is intrinsically deleterious to the nation’s military organization and will inevitably weaken even the most dominant military power. And this weakness is distinct from the separate problem of foreign military commanders whose loyalties tend to be outweighed by either their ethnic interests or their self-interests.
As he demonstrates in the first chapter of his excellent essay, now being serialized at Castalia Library, the Roman Empire suffered both of these negative effects........
