A key to America's prosperity is that we have not shared a border with an adversary for over 200 years. This madness is not just pissing off a (literally) close ally, it's making a foundation for future unresolved conflicts.
This administration does not understand history, and takes peace for granted.
But since those times, lots of peace and goodwill with our neighbors, which is condusive to prosperity.
[1] https://en.m.wikipedia.org/wiki/Pig_War_(1859)
[2] https://en.m.wikipedia.org/wiki/Mexican%E2%80%93American_War
That's simply not true, as the Mexican-American War of 1846-1848, the various border conflicts with Mexican forces and factions during the Mexican revolution, etc.
Also, the conflicts with Britain (which includes Canada) through mid-19th Century (particular flashpoints including the Pig War. Aroostock War, and Trent Affair.)
But the key point here is that some US leaders clearly understood it as a principle pretty early on even if they struggled to enact it at first.
Global stability, peace, preserving what's left of America's affable reputation...
these things certainly are important to me, but maybe not to them.