As I write these lines, innocent civilians are killed or threatened by rulers, warlords, or other groups throughout the world. As some of you know, for many years I have argued that humanitarian intervention (the use of force to save lives in such situations) is sometimes permissible. A standard libertarian objection is that a government should not force people to subsidize wars in defense of others (these objectors may or may not think that a government can force people to subsidize wars in self-defense).

Here’s a reply to the objection: those private citizens who wish to save lives in other nations should themselves hire professional soldiers (mercenaries) to do the job. In that way, rescuers internalize the costs of their humanitarian impulses. No standing army or conscription is needed, and citizens cannot possibly object to humanitarians putting their money where their mouth is.

My proposal involves filibusters and mercenaries. Filibusters are persons who wage unauthorized wars -that is, unauthorized by the state. Mercenaries are persons who offer military services for a price. So, I suggest that filibusters (who are private persons) can hire mercenaries (who are also private persons) to put an end to massive crimes in other states. Take them in turn.

1) As indicated, filibusters are persons who wage unauthorized wars. Under traditional just war theory, private wars are impermissible. Here is St. Thomas Aquinas: “It does not pertain to a private person to declare war, because he can prosecute his rights at the tribunal of his superior; similarly, it does not pertain to a private person to summon the people together.” (Political Writings, Cambridge U. P., 240) Just as the government is in charge of punishing criminals within the state, so it is in charge, as Aquinas says, of using “the sword of war” to protect the state from foreign enemies. The idea, then, is that the state has the monopoly of both domestic and external force. Starting a private war usurps that monopoly.

But why can’t private persons organize themselves and travel to a territory to help victims of genocide? Such initiatives will solve a pervasive problem in the justification of war: the state’s forcing unwilling citizens to participate in or subsidize a humanitarian intervention. There is sense in the common say: “Do you care about the Congo victims? By all means, organize your own army and intervene there on your dime!” (In fact, a good deal of the hate mail I receive starts exactly like that). The filibuster does not impose on others the costs of intervention. It is no answer to say that in today’s world private wars are unrealistic and unfeasible and the state is the only entity capable of starting a humanitarian intervention. The issue is why, assuming some wars are just, filibustering should be prohibited as a matter of principle.

Filibustering, of course, is not well regarded by international law, which makes governments liable for any military operation. But this is just more evidence that international law overprotects governments. A justified war is a form of justified defensive action (humanitarian intervention is also defensive action, an action in defense of persons). The requirement that actions by individuals in defense of people in foreign territories should be authorized by the state of which those individuals are nationals is, I think, arbitrary. If anything, the requirement that only the state can initiate war makes even less sense in humanitarian intervention. For in that case, the defensive action by filibusters on behalf of foreigners occurs outside the jurisdiction of the state of which the filibusters are nationals. In national self-defense, the state arguably has authority in its territory to lead and coordinate the defensive war. But that authority does not reach those who fight to save others in foreign lands. The idea that the state is the only entity that can or should start a war is just another statist prejudice.

Filibusters can be billionaires imbued with the desire to rescue victims of genocide, or grass-roots organizations that crowd-fund humanitarian military efforts through small donations from many like-minded people.

2) Mercenaries are private entrepreneurs who offer military services. As long as they have existed (since Antiquity) they have been despised by governments, scholars, and the general public.

However, an unprejudiced look reveals that most of the reasons for this hostility are questionable. It is argued that because killing for money is morally wrong, it is impermissible to hire people who do that. But surely enlisted soldiers kill for money too: it is their profession. Arguably, enlisted soldiers risk their lives not only for love of country but also for solidarity with comrades. If this is true, then it seems equally true of mercenaries, who presumably take pride in what they do and feel solidarity for their comrades also. Monetary compensation is one element in a richer range of motives, many of which are self-interested. Enlisted soldiers receive salary, benefits, prestige, and social esteem. All of these motives are self-interested, yet a romantic tradition has emphasized the honor and glory of fighting for one’s country –I call it the Patriotic Prejudice. Because this altruistic motive seems to be lacking in mercenaries, they are supposed to be bad people. But once we disaggregate motivation in both cases and we see the Patriotic Prejudice for what it is, the two cases do not seem that different.

This proposal is only partly tongue-in-cheek. I think that the only reason why it sounds so ludicrous is that we have been indoctrinated with the idea that only nations can wage honorable wars. I conjecture that for centuries rulers have peddled the Patriotic Prejudice to motivate subjects to give their lives for the rulers’ benefit.