The only legitimate justification for something like a “national border” would be to separate a free territory from any unfree territories around it. In order to protect the people in the free territory from the statists surrounding them.
This situation doesn’t exist anywhere in the world because there are no free territories (other than small scale experiments, maybe). America hasn’t been a free territory since America was replaced by “the United States” with the ratification of the U. S. Constitution. As long as there are “taxes” and other counterfeit “laws” and politicians in a territory, it is not free. Even though there are differences in degree, there are no differences in kind.
As it is, national borders are rather like the internal fences in a feedlot. They separate different groups of cattle from each other for the purposes of those who exploit them. It’s not for the good of the cattle. It would be genius to brainwash the cattle into believing it is.
In our human situation, it’s as if the cattle in one pen are getting angry at the cattle who hop the fence instead of focusing their anger at those who manage the feedlot. “We must remain ‘King of the Dung Heap’ in our little pen!”
Those humans who hop the fence may be hoping to avoid a looming appointment on the kill floor, or maybe they hope for more food on the other side. But if they are looking for liberty they are doing it wrong and looking in the wrong place. Still, I can’t blame them for doing something in their desperation, even if it amounts to jumping out of the fire and into the smoldering kindling.
And, the ones who hop the fence and then demand to make this side similar to the side they were desperate to escape are being stupid and are committing evil.
To be clear: nothing excuses archation by fence hoppers. Nor by fence defenders.
Instead of abandoning principles over your “border”, why not make this side of the fence free. Create a condition of liberty. That means zero “taxes”, zero counterfeit “laws” of any kind, and zero politicians. This side of the fence cannot be a State.
Then, and only then, I’ll help you secure the border from anyone who tries to bring a little bit of archation into this free territory– while welcoming all others (because they couldn’t be a problem). Anyone else should be free to cross this border in either direction with no delay or difficulty whatsoever.
Because it’s always up to the believers to convince the skeptics, it’s up to those who support the “borders” to make this a free territory and convince me to support their walls and fences. If they have a workable plan which doesn’t involve me compromising food with poison or liberty with statism, I’ll jump right in.