Probably to stop refugees. Many of whom would be somewhat unsavory.
I don’t know.
I’m listening to the rhetoric here, and it’s assuming the character of an anti-Russian crusade. “We must save our Ukrainian brothers from the Russian savages!” That sort of thing.
The Russians are certainly not well loved here. Some of the pro-Russian rhetoric I see on the internet would be an invitation to a punch in the face in this part of the world.