[syntern]

It has nothing to do with the size of the country. The US sees immigration as a privilege offered to a lower being [note], while Singapore sees (qualified) immigration as a way forward.

[note]: This may have been true for a long time in the history. People were going to the US mainland because their conditions were bad enough, and anything would have been better elsewhere. I can understand that point of view, although e.g. my situation is on equal terms in the US vs my home country. However, I don't think it'll serve the US interest in the long run.