That's the point I got. If you fail to organize and fight the invaders when they are few, then you will eventually face a more populous enemy and may well lose everything you have to them.
Works for me.
One of my favorite quotes by Winston Churchill:
“If you will not fight for right when you can easily win without blood shed;
if you will not fight when your victory is sure and not too costly;
you may come to the moment when you will have to fight with all the odds against you and only a precarious chance of survival. There may even be a worse case.
You may have to fight when there is no hope of victory, because it is better to perish than to live as slaves.”
I don’t know how it is in the west, but in the south there has been intermarriages between the people for so long that many would be surprised what their bloodlines could show way down the line...
I am Scots/Irish and Ani-Yun-Wiya that I know of, but there is probably British, Dutch, German, and African blood in there also...