The greatest threat to national security, to our freedom and our future, isn't the weather. It's migration. In ancient times wars began when nomadic groups migrated into someone else's territory. Today it's our territory that's being migrated into.

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Once all the migrants, who are in the majority young men, are accounted for, the median age will be even lower. You hear a lot of worries about some European countries on the migration route ending up with more migrant men of fighting age than exist in the native population. That's effectively an invasion.

But when you're talking about countries with low birth rates, it's not that hard to achieve a scenario where the young male migrants displace the young male population of the country.

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The Muslim world has a large disposable young male population. A chunk of that population is making its way to Europe even as we speak. It seems like a big chunk to us, but by their standards, it's hardly noticeable. It's that disposable young male population which doesn't bother to get jobs, which parties and does drugs, then suddenly finds religion and redemption by killing a whole bunch of non-Muslims.

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The real national security threat comes form the oldest form of war. Migration.

Entire civilizations were wiped out by migration. If we don't shut the doors, we might become just another footnote in someone else's ancient history.