It was, I think, among the first SF books I ever read. I don't think I can remember the first time I read it

She had her facts.

OTOH, even in The Prince Commands, she had her basic plot down flat. Here is an Andre Norton story; stuff marked "usually" or "may" happens in about two-thirds, three quarters of them.

A character, usually young, is in a place where he does not fit in. Under some pressure, he is precipitated out of it into another place, though usually he has some choice in the matter. There is also a problem in this new place, which may or may not send him onto another -- which can even lead to a chain of places he goes through.

If old enough, he may meet the Love Interest along the way.

Finally, he hits a place where he and the Love Interest resolve their subplot if there is one, and he (with Love Interest if there is one) resolves the problem.

If this makes him welcome there, he (and the Love Interest) will settle down there, in a new place where they fit.

If it does not make him welcome there, he has a Love Interest, and they go onward. This may lead to a sequel where they continue the chain of places until they do find a place where they are welcome and fit.

I don't think it's so much predicated on World War II as it's the natural thing for her to subject her protags too.