[_dps]

It's important to note that the Schengen agreement was only about travel, and not what what is commonly assumed these days regarding border debates: the ability to come, settle, work, and take part in the social safety net.

Switzerland for example was a Schengen signatory. Switzerland has never allowed open immigration, work permits, or welfare benefits for people entering under Schengen terms.

So while I think you give a good example of what can happen in 50 years, I think it's very important to draw a distinction between Schengen-like agreements and what people commonly understand from the closed/open border debate.