Obvious steelman , which I ' m surprised hasn ' t been presented yet it ' s fairer , or at least it ' s perceived as fairer . If you ' re going to have borders at all , it ' s a lot less contentious to have a rule that says you have to be an American than a rule that says you have to be the Right Kind of World CitizenI believe it ' s something similar to that . Lines need to be drawn . The line between the US and Canada may be arbitrary but it ' s possible to have a good deal of consensus about it . i . e . it ' s a Schelling Point . Here ' s an analogy Suppose you are one of 20 people on a lifeboat . You have 2 or 3 friends and the rest of the people are complete strangers . You may not be thrilled about the strangers , but you all got on a few days ago and you have developed an uneasy accommodation for each other and even a vague sense of camaraderie . A few days later another 10 strangers want to climb on board which you know will make life a lot worse on average for people already on the lifeboat . You may care about those new strangers only slightly less than you care about the old ones , but the people already on the boat might reasonably agree to exclude the new people . For the simple reason that this boat belongs to the original 20 is a guiding rule which everyone can agree on . Just as with national citizenship , a line needs to be drawn . And an arbitrary line which most people can agree on is better than no line at all . Heck , even if the next day , 5 new people show up who want to climb on board and they are all your friends , you might still reasonably oppose it on the ground that it will lead to the breakdown of consensus . lazygraduatestudent argues that having rules like this can sometimes lead to results which are inefficient , unfair , or nonsensical . Which is of course correct , but that ' s always the case with rules . And clearly when it comes to nationalism , rules are necessary . Because the United States simply doesn ' t have the resources to provide Medicaid or other government services to everyone who would show up if we tried . I should also poison the well a bit by noting that I ' m skeptical that lazygraduatestudent seriously believes in the principle that nationstates should care equally about citizens and noncitizens . Let ' s see him or his ilk call upon the socalled State of Palestine to offer full citizenship to any Jews who happen to be living in Judea and Samaria . Or for that matter , for countries like Kuwait or Saudi Arabia to share their oil wealth with the entire world and offer full citizenship for anyone of any religion who wishes to immigrate .