How Fragile Are Ecosystems?

From Letter from Gotham:

There's nothing wrong with the French model of assimilation. It's worked beautifully with a variety of previous emigrants, which included Arab Muslims and Iranians. The problem is the NUMBERS. You can't assimilate huge amounts of people who speak a different language and worship a different God, especially Allah, a very masculine warrior sky-god. Something's got to give. A society is as fragile as an ecosystem. France will survive...but it is suffering a terrible case of indigestion.

Does that mean the fragility of societies has been greatly exaggerated by would-be dictators?