>Switzerland is a land-locked village with fewer people than <one of the biggest cities in Europe> and entirely dependent on trade and the movement of people and money for all they have, and barely a scrap of a language to call its own.

Everything in that quote has been always been true though, and my guess is that they never allowed significant numbers of migrants at any time from about 800 (i.e., after the end of migration period) until whenever they started letting in large numbers of immigrants (some time after 1990 probably) (but not large enough numbers to suit you, I gather).