Unlike the ”Green Card” issued to all permanent residents, this document is not mandatory. The American “Green Card”, on its own or in conjunction with a passport, is valid for international travel albeit not to the same extent as the re-entry permit. Both documents can be utilised to clear American border controls regardless of the bearers nationality, thus resulting in America not requiring permanent residents to hold a passport from their home country in order to remain lawfully present or to lawfully enter.