Libertarianism

Libertarianism is what you get when you attempt to merge the capitalism with pacifism. It is an unstable system which is closer to anarchy than conventional capitalism because it applies skepticism to all international relations. For instance, only retaliatory force is considered appropriate, not proactive measures to prevent destruction. Under libertarianism, you do not have a right to attack a person who is preparing to attack you, even if you wouldn't be able to attack them once the threat becomes "proven". Of course, because the libertarian is a skeptic, very little will convince them that there was a threat short of actual initiation of force. For an analogy of libertarianism in simple terms, the right to respond comes not when a person pulls their arm back to punch, but when they are in the process of actually punching.

Objectivism differs from libertarianism in this respect. A person, according to Objectivism, can have confidence in their own judgemental capabilities and determine that someone is a threat without there being any imminent signs. Rather, a person can judge from a person's character, both social character AKA will to attack and productive character AKA capacity to attack, not just immediately, but sometime in the future. Of course, in a social context where the authority in question is reliable (IE both qualified and trustworthy) to respond, one should rely on the authority, since they have a rightful monopoly of force. However, international situations are no such social context, and so action must be taken by the nation being threatened and its allies against the threatening nation and its allies.