Of course, to question whether Americans would permit a “hostile” presence on our borders is to beg the question of what, exactly, is truly hostile about Ukraine. It’s a nation still newly freed from the Soviet empire, it possesses a fraction of Russia’s military power, and it has absolutely no designs on Russian territory. Despite Russian fears, it seeks membership in NATO as an act of self-preservation, not as a first step to conquest…

To the extent that Ukraine is a threat, its democratic example is a threat to Russian authoritarianism. By contrast, a thriving democratic Mexico or Cuba isn’t remotely a threat to the United States. It would be a blessing, just as a thriving democratic Canada has been an asset to American peace and security for generations.

In short, there is no moral equivalence in the way that Russia and America view their respective “near abroads.”

But let’s dive even deeper. Beyond the moral principles, there are three major reasons why Americans should be alarmed about Russian aggression. I’ll address each one in turn.