Immigration Versus Invasion?

One more thing and then I'll shut up. The difference between immigration and invasion warrants further discussion.

Say Mohammedan hordes wielding AK-47s land on the shores of Sicily. After a campaign of rape and plunder, vigorously resisted by the Italian government and armed local militias, they institute (freelance) Sharia law at the point of their guns.

Now say unarmed Mohammedan hordes swarm the shores of Sicily. After a campaign of rape and plunder, dutifully ignored when not enthusiastically subsidized by the oh-so-tolerant Italian government, they seize the machinery of democracy and vote themselves (government-payroll) Sharia law.

What's the lesson here? That Sicilians and "their" government ought not to resist the armed invaders because the Mohammedans can just as "peaceably" seize the machinery of democracy and vote themselves (government-payroll) Sharia law?

Left-libertarians get right-libertarians all wrong. We don't want to enlist the government to keep our ancestral homelands free of alien and hostile elements. We don't even trust it to do that. We want separation of borders and state.