Can anyone name an example of a country that fared poorly as a result of having a really open immigration policy?

by EngineeringNeverEnds
brigantus

Our subreddit rules don't allow "throughout history" questions, so I'm afraid I've had to remove your post. We've found that questions like this end up attracting low effort trivia rather than the in-depth responses people like to see here. If you're interested, I'd encourage you to post a question about immigration policy in a specific time and place.