Restrictions on the free flow of people are not a binary decision. Countries in the Schengen Area which have almost completely given up the ability restrict movement between their territory and 25 other nations are not restricting the movement of people as much as say North Korea which doesn't even let most of its own citizens travel abroad.
https://en.wikipedia.org/wiki/List_of_sovereign_states_and_d...
And it seems to me that it's that lack of "nationalism" as you've defined it that's helping US-based companies exploit cheap labor in (or from) other nations.
And of course, restrictions on freedom of movement can't be summed up exclusively with number of immigrants. There are many countries that are much, much easier to get into than the US; people just don't want to go there as much. And of course, nationalism isn't exclusively border control. That is just one nationalistic behavior.
If you're intentionally misinterpreting me, this discussion isn't going anywhere. But in the hope that that's not the case, I'll try again:
What country offers freedom of movement to the most people? The US, by far.
The freedom to move from France to Germany, or from California to New York, has nothing to do with the freedom of movement of people born outside those systems.
The constituent countries in the EU are still sovereign countries. Unlike US states, they are free to leave at any time.
The EU already has a parliament, "federal" laws, and a single currency. They're building an EU army and discussing federal taxes. At what point do you call them a nation?
Loosening restrictions on select people is not loosening restrictions on everyone.
Vatican City, with their tightly controlled migration policy, is not the country with the most freedom of movement simply because they allow freedom of movement to carefully chosen people.
In the Vatican, for example, a given person either has a 100% chance of migration or a 0% chance. Israel has similar numbers. In the Schengen area, it's either a 100% chance or a very small chance.
Update:
Perhaps this will be clearer. Every free country grants total freedom of movement to some group of people. In Israel, this is Jewish people. In the United States, US citizens. In the Schengen area, citizens of the Schengen area.
What does that have to do with nationalism? Nationalism is a distinction between the treatment of in-group people and out-group people.
In the Schengen area, people from the Schengen area are the in-group.
Changing loyalty to a larger nation isn't the same as becoming less nationalistic.
It doesn't even have a shared government to try to make it fit if you are trying to use "nation" as a synonym for "country". Most of the countries are part of the EU, but Iceland, Liechtenstein, Norway, and Switzerland are part of the Schengen Area but not the EU.
Are you saying Europeans don't have any descent, history, or culture in common?
There are some groups of countries that have some descent and culture in common like Portugal/Spain or Benelux or Scandinavia, but there is no pan-European culture. Portugal, Greece, Monaco, Latvia and Iceland have almost nothing in common.
Spain is a lot closer to Morocco than to Norway, but Spain partnered with Norway rather than Morocco because they share the same descent (European) and culture (Christian).