[johnmorrison]

The governments in those countries have enough resources to buy enough land in colder areas for all their people. Would definitely be economically disadvantageous for the migrant nation, but there's no reason it needs to cause "global thermonuclear warfare"

[ncmncm]

I see that you have very little acquaintance with politics as it is practiced.

What we see happening in the US, with the small amount of migration occurring so far, is spending $billions on building walls.