The question of humanitarian intervention is also worth 'pondering in the Arendtian distinction between power and violence. Arendt sees power as a social thing, not a property of an individual: "Power corresponds to the human ability not 'just to act but to act in concert...; it belongs to a group and remains in existence only so long as the group keeps together." Violence, on the other hand, is instrumental; "like all means, it stands in need of guidance and justification through the end it : pursues.” If power is a social thing, then it "needs no justification, being inherent in the very existence of political communities; what it does need is legitimacy." Here the difference between legitimacy and justification is that the former is a priori-it relies the "initial getting together-while the latter is a posteriori-it” relates to an end that lies in the future.” Arendt insists, “Violence can be justifiable, but it never will be legitimate. Its justification loses in plausibility the farther its intended end precedes into the future." "No one," she continues, "questions the use of violence in self-defense, because the danger is not only clear but also present, and the end justifying- the means is immediate." She also points out that the loss of power becomes a temptation to substitute violence for power...and that violence, itself results in impotence." So violence reveals the powerlessness of power.