Russians have had to live through many devastating invasions. US only recently, from the south. Our government appears to be embracing that one, however.
Given that the Russian homeland has been invaded by the Mongols, the French and the Germans historically, small wonder why Russians have a fear of invasion ingrained into their culture.
Machiavelli in “The Prince” “Keep an enemy at the gates even if you have to pay for him yourself”.
Pols have revered this advice for generations.