The Achilles Heel of Libertarian War Theory: Who Decides?

Can a libertarian support or engage in war? Some libertarians point to the right of self-defense to justify going to war. An individual has the right to defend himself with deadly force, if necessary, against an aggressor. If you multiply the justified individual by hundreds of thousands, they argue, then you create an army of people who can collectively and rightfully exercise their self-defense. From this point, debate on the propriety of a libertarian war usually revolves around issues such