I would like to add that we often wish to invite professors from Japan's national universities to lecture in Taiwan--say, some of my old classmates or world-renowned scholars--but Japan will not give them passports, because they are professors at national universities.
簡單再加一段話，日本國立大學教授，我們請他來台灣講課，比方說我的老同學以及世界有名的學者，日本卻不給他護照，因為他是國立大學教授。