Let’s see here, if I’m not mistaken France had a fortified border keeping the Germans from invading them. Oh wait a minute, the Germans just went around the fortified border.
A fortified border is a good idea, but not the answer to any country that wants to invade.
I honestly do not think Russia’s military is a match for anything the West has. I don’t think Poland is one of Putin’s targets.
Pray tell, what route would Russia use to attack Poland if Russia does not attack from Belarus or Kalingrad?
Go through Latvia and Lithuania, bringing NATO into the conflict a minimum of a few weeks sooner?
Go all the way through Ukraine to its North-Western oblasts? Hot progress would be about a km a day...
The situation does not remotely mirror France in WW2.
Poland will not be a target of Pooty precisely because Poland is rapidly building up its defenses in all ways except going nuclear. Well, at least I don’t think they’ll go nuclear...