Why isn't screening tech globalized on a planetary level? Shouldn't someone like INTERPOL take care of that?
I doubt the US would ever outsource something like this (border security) to an international organization like INTERPOL. It uses INTERPOL to track down and catch wanted people abroad, but that's it.
No chance the world powers (US, China, France, UK, etc.) will allow something like that unless they are the one who create and enforce it. It's basically the first line of defense for homeland security: don't let terrorists into your country.