I’m going to try to clarify the “Monopoly Of Violence” argument in Propertarian terms: All human existence can be reduced to property rights.

    1. All human beings object to involuntary transfer of what they worked to obtain, by theft, fraud, or violence, and whether that transfer be direct or indirect.
    1. All societies have collections of property rights.
    1. These rights exist along a spectrum that consists of individual, shareholder, and collective property rights.
    1. Those property rights can be constructive, neutral or destructive. They can be just or unjust. They can be dominated by egalitarianism, expropriation, or meritocracy or a combination thereof.
    1. Those rights are met with corresponding obligations we call norms: forgone opportunities, manners, ethics, morals. They are, in large part, prohibitions on involuntary transfers of property.
    1. And these obligations are costs. They are the cost of the institution of property. People feel that they ‘own’ their institutions because they ‘pay’ for them.
    1. Since any foreign group’s portfolio, upon interaction with the home group’s portfolio, will by definition and necessity cause involuntary transfers from any home group, and the inverse, then groups use violence to both to institute their property rights and obligations and to prevent involuntary transfers both inside and outside of the group.

Groups have different property rights. Even among libertarians, we disagree upon warranty, symmetry, external costs and the right of exclusion. All groups, regardless of their portfolio, pay for property rights with forgone opportunities for violence, theft, and fraud. And the promise of violence remains whenever violence, theft, and fraud are committed.

Therefore, people are ‘justified’ in protecting their property. Their property rights themselves are a form of property. They are justified in forming a group that mandates those property rights. They are justified in combating a government that abridges or abrogates those rights.

You can run on with this reasoning and answer almost all political questions. However, to answer yours, directly, we need to understand that one does not ‘justify’ power. One exercises it to achieve one’s preferences, and either has the power to achieve them or not. Justification is an attempt to achieve one’s preferences at a lower cost, or to lower the cost of maintaining those preferences. But that is all.

So your question implies a universalism that is not present in political action.

https://www.quora.com/What-is-the-justification-for-political-authority-enforced-by-force