"When the contest is only with native rulers, and with such native strength as those rulers can enlist in their defence, the answer I should give to the question of the legitimacy of intervention is, as a general rule, No. The reason is, that there can seldom be anything approaching to assurance that intervention, even if successful, would be for the good of the people themselves. The only test possessing any real value, of a people’s having become fit for popular institutions, is that they, or a sufficient portion of them to prevail in the contest, are willing to brave labour and danger for their liberation. I know all that may be said, I know it may be urged that the virtues of freemen cannot be learnt in the school of slavery, and that if a people are not fit for freedom, to have any chance of becoming so they must first be free. And this would be conclusive, if the intervention recommended would really give them freedom. But the evil is, that if they have not sufficient love of liberty to be able to wrest it from merely domestic oppressors, the liberty which is bestowed on them by other hands than their own, will have nothing real, nothing permanent. No people ever was and remained free, but because it was determined to be so..."Mill's argument for humanitarian intervention, however, is not compatible with modern international law. International law after World War II establishes the principle of sovereign equality, and therefore to subject a sovereign state to outside intervention is generally considered illegal. To deal with this potential conflict between humanitarian intervention and the international legal system, there are some philosophical attempts to conciliate the two concepts and specify conditions for ethically justified interventions. John Rawls, one of the most influential political philosophers of the twentieth century, offers his theory of humanitarian intervention based on the notion of "well-ordered society." According to Rawls, a well-ordered society should be peaceful and legitimate, and it must respect basic human rights. Between such well-ordered societies, the principle of non-intervention should uphold. On the other hand, expansionist or human rights violating regimes are not shielded from the international law: in grave cases such as ethnic cleansing, coercive intervention by others is legitimate.