So are you saying Trump should build a zigzag fence? That's actually a super interesting fact about castle building, I'll pay more attention to that next time I'm somewhere with enough history to have had castles.
The zigzag aspect of it is a function of fortification. They're pointy like that because there's no "lee" under the turret to hide in and because everywhere you can approach it, you can be shot at from somewhere they're defended. Obviously if you could just pound the shit out of it with cannon you'd be golden but around that fortification is a ditch where they get to kill you, then a moat, then a glacis which is angled to deflect cannon fire. Obviously this can get iterative - moat/glacis/scarp/parapet/moat/parapet/etc until the only way either side can move is if one side starves the other out. Trump's tax plan is going to do a lot of starving the other out.
If forts count, Canada has some pretty cool ones. https://en.wikipedia.org/wiki/List_of_forts#Canada Clicking around randomly, Fort Beausejour was a star shaped fort. Sadly, all that are left are some ruins.