[ubernostrum]

Keep in mind that perception matters a lot. This is, for example, a big part of how the TSA obtains "cooperation" from air passengers in the United States -- even though they aren't law enforcement and can't perform law-enforcement tasks like arresting people, everything about the way they present themselves (uniforms, badges, etc.) is designed to create the perception that they are and they can.

So if I'm on a train and it stops at the border, and a uniformed government official comes in and asks to see my passport and then starts asking me immigration questions, the perception is not "this is an uncontrolled border, just got a random check that could have happened anywhere in the country". The perception is not "oh, this officer can't actually deny me entry".

The perception is "this is an immigration check at the border", and the dynamic of the situation flows from there.

The ticket checking by rail crews does seem to be an entirely German thing (again, other countries' rail crews just had a list and marked which seats had been checked, so even if another crew or crew member came through later they didn't need to repeat it), and I suspect there's a larger cultural pattern here tied into things like the German identification-obligation laws (which, to be honest, made me more than a bit uncomfortable when I learned about them -- I have enough trouble with the idea that in my home country courts have ruled I can be subjected to an ID check at any time, learning that it's still a deeply-ingrained thing in a country with Germany's history is off the scale of unsettling for me).

[lispm]

> So if I'm on a train and it stops at the border, and a uniformed government official comes in and asks to see my passport and then starts asking me immigration questions, the perception is not "this is an uncontrolled border, just got a random check that could have happened anywhere in the country". The perception is not "oh, this officer can't actually deny me entry".

If you travel in a foreign country, you might want to make yourself familiar with the usual regulations.

> The ticket checking by rail crews does seem to be an entirely German thing (again, other countries' rail crews just had a list and marked which seats had been checked, so even if another crew or crew member came through later they didn't need to repeat it),

You can easily see that this does not work.

> identification-obligation

I fail to see a problem with having a passport.