  An argument as elaborate as this one obviously depends upon a number of controversial premises about the best, most realistic way to help the world’s poor and the likely future conduct of wealthy liberal democracies. It is also important to recognize that, even if each of these claims is accurate, this argument does not establish the type of conclusion that many defenders of closed borders might want. This is for two reasons. First, rather than establish a state’s moral right to exclude outsiders, it would seem to show at most that we should treat states as if they had this moral right by, for instance, respecting their international legal right to design and enforce their own immigration policies. Second, this argument’s conclusion would not hold indefinitely; rather, the argument would apply only until the desired international institutions were constructed. Once the geo-political environment was suitably repaired, this particular argument would no longer provide any reasons to resist open borders. Of course, most cosmopolitans will regret neither of these features of this argument, but many who seek to defend a state’s right to exclude outsiders may well be considerably less sanguine about such limitations.