The only border we had in 1789 was 2000 miles of ocean. We didn’t need the army on the border to prevent an invasion. Right now we have a porous southern border that is being constantly invaded. We need the military there. We still have a standing navy of the ocean fronts but nothing covering about 5000 miles of open land to the north and south.
Wastedyears is correct regarding a standing Army. Given the Brit Army occupation of Boston, Charleston, and New York, the topic figured bigly during the ratification debates.
I say declare martial law at the border. It is time to pull the matter from judicial oversight and turn back, without due process, every invader.