Also, keep in mind, EVERY single nation-state in existence today was artificially created by someone, at some point, securing a piece of land (or sometimes several non-contiguous pieces) to mark invisible borders around and get a system of laws and order and governance established, and have it recognized by enough relevant nation-states already established to make it viable. These are not natural, organic, intrinsic institutions like nationalists often portray them as, and, technically - and theoretically - they're always up for renegotiation - internally and externally - with enough military, political, economic, and/or cultural clout. As an astronaut from the ESA said after first setting foot on the International Space Station and looking down from an observation window, "you cannot see international borders from space."
Much of what many nations-states started to do was copying from its small scale predeccessor, the medieval town.
And yes... the former colonies have that phase not as part of their history (like the US) and yes... former very imperial absolute monarchy countries have another balance of history between local towns and "the Capital"
Until the Napoleontic occupation we had ofc already 200 years the Dutch Republic as superstructure, but all kinds of rights and duties regarding "citizens" were tightly and precisely in place for townsmen in towns.
The Dutch word is "poorter", someone with rights, privileges and duties inside the "poort", the gate of the town. => the protection of the town, mostly behind walls of the town. But also as traveller in other towns !
You could buy that status, you could marry in that status. And without that status you could not be part of a Guild. If parent "poorters" died, their children were taken care of in an "burgerweeshuis" a burgher-burgess orphan house. A right not available for "foreign" town dwellers.
Some "poorters" had more privileges than others. The ones with more privileges in the Low Lands more like what an English "burgess" is.
If I as "poorter" of Amsterdam committed a crime in Antwerpen (Anvers) I would be tried and convicted in Antwerpen according to Amsterdam Law, according to the "City Rights" of Amsterdam.
Medieval time in (at least the Low Lands and the highly fragmented Holy Roman Empire) is a big oceanlike continuum of cultures, languages, ethnicities, etc with as superstructure a much less fragmented HRE Law and everchanging nobility rulers that are mere passers by !
And in that big ocean there were everywhere dots with their own "nation-state like" more detailed and restricting laws, rights, regulations (on everything !!!), traditions. Nobility rulers gave in the late medieval time more and more towns those City Rights in exchange for a big lump sum of money. And mostly a town getting city rights would decide to copy them from this or that other town (the noble ruler playing a role in that). And in complicated court cases, the young town would often postpone the court case and seek legal advice from the mother town. It was all in all both a semi-chaotic process as a process with many converging mechanisms.
You could say in a sense that the first order range of the "town-state" was determined by the height of the Church tower with the bells ringing the hour of the day and often that new tech "a town clock" visible for everybody and bordered by the town walls.
After all... the "foreigners" not being a "poorter" or even a "town dweller" had to have left the town, before the gates would be closed for the late evening and night.
Being expelled, banned, from a town was a common punishment for not abiding to the rules of the town.
But if you look over time how towns in the sweet spots grew, migrants were absorbed all the time, and exchange of everything between towns was massive.
And the diversity of medieval time is the positive side of the coin of the fragementation felt today by many.
That typical uniformity culture, especially getting strong around the time of Napoleon, not only the military uniforms, but especially rules to be applied far outside their high return meaningfulness, the "national language", so much more.
Compare above medieval situation with:
* A US citizen runs into problems somewhere in the world, and the strong reaction of the US government to "protect its citizens" all over the world and the rope pulling which court or which prison applies.
* The rights on social security etc for nation-state citizens with foreigners (that orphan house).
* The international character, the supranational structures and the ruling high nobility and the rivalry of those kings etc with the lower nobility more bound to an area (the current national structure).
* The overstretched imperium issue of the absolute empires, surpressing local identies in medieval up to modern times, and the drive for local self-determination.
* The converging character of town rules, laws, regulations on everything by best practice sharing between towns moderated in speed by local traditions (fundamentally a bottom up & peer to peer process)
The way nation-states are spreaded over the European surface is purely historical based from that rather small period in time that so many techs evolved (economical, military, communication, etc) helped by scale size and enabling better top down control.
But those nation-states are imo only the current superstructure and has mostly not been able to root out centuries of the old continuum structure, properties and importantly social mechanisms.
As yung.carl.jung mentioned in an earlier post here (I was tempted to add a similar remark
but more fluffy about the fairy tales with a hero travelling past 7 kingdoms to finally rescue the princess, but not before he chopped, felled seven trees with only one axe blow, to win a local contest (Russia has always been part of that continuum before the nation-states emerged):
in the next few decades national identities will be completely abandoned anyway, we are just ahead of the curve.
What the EU is doing... is finding out by doing.... by bargaining between all inputs and convictions.... is imo how to shrug off those WW1 & WW2 heritage and get back to that medieval ocean, get that continuum back, toggling between the necessities of scale size here (in pooling and rules and yes.. also protection) and local determination (or bottom up as it happens) there. A complex hybrid instead of systemic uniformities, and imo much closer to local society and free citizens.
I doubt that this process is well covered by newsmedia in many countries. Especially countries with a higher percentage of people and politicians favoring a federal Europe. International (English written) newsmedia, their political reporters, having anyhow no clue, no feel at all, on the processes and history I described above. With imperial spectacles you dont see much on what happens on the shopfloor.
Not only for a modern US astronaut there are no visible borders.
They never were there for medieval, early modern scientists and philosophers, nor for traders and entrepreneurs.
And why would young EU citizens of today need any borders ?