International Relations, Political Science, Pre-Law and related fields.
Organizations that would hire non-U.S. nationals:
- Humans Rights Watch
It says on every professional-level job that “HRW will pay reasonable relocation expenses and will assist employees in obtaining necessary work authorization, if required; citizens of all nationalities are encouraged to apply.”
The UN also hires according to nationality if you pass their comprenhesive examinations and testing.
I will search for more, now that I know the keywords.
The United Nations also likes non-US citizen nationals. Of course, most jobs require several years of professional-level experience.