Even ancaps have the idea of the NAP, which is a social contract to not physically attack people unless they are defending themselves.

Hobbes also seemed to think that kiling people is part of human nature, which makes sense if you are part of an imperialist colonization project.

from Leviathan section "The Incommodites Of Such A War " https://www.gutenberg.org/files/3207/3207-h/3207-h.htm#link2H_4_0091

" Whatsoever therefore is consequent to a time of Warre, where every man is Enemy to every man; the same is consequent to the time, wherein men live without other security, than what their own strength, and their own invention shall furnish them withall. In such condition, there is no place for Industry; because the fruit thereof is uncertain; and consequently no Culture of the Earth; no Navigation, nor use of the commodities that may be imported by Sea; no commodious Building; no Instruments of moving, and removing such things as require much force; no Knowledge of the face of the Earth; no account of Time; no Arts; no Letters; no Society; and which is worst of all, continuall feare, and danger of violent death; And the life of man, solitary, poore, nasty, brutish, and short.

It may seem strange to some man, that has not well weighed these things; that Nature should thus dissociate, and render men apt to invade, and destroy one another: and he may therefore, not trusting to this Inference, made from the Passions, desire perhaps to have the same confirmed by Experience. Let him therefore consider with himselfe, when taking a journey, he armes himselfe, and seeks to go well accompanied; when going to sleep, he locks his dores; when even in his house he locks his chests; and this when he knows there bee Lawes, and publike Officers, armed, to revenge all injuries shall bee done him; what opinion he has of his fellow subjects, when he rides armed; of his fellow Citizens, when he locks his dores; and of his children, and servants, when he locks his chests. Does he not there as much accuse mankind by his actions, as I do by my words? But neither of us accuse mans nature in it. The Desires, and other Passions of man, are in themselves no Sin. No more are the Actions, that proceed from those Passions, till they know a Law that forbids them; which till Lawes be made they cannot know: nor can any Law be made, till they have agreed upon the Person that shall make it.

It may peradventure be thought, there was never such a time, nor condition of warre as this; and I believe it was never generally so, over all the world: but there are many places, where they live so now. For the savage people in many places of America, except the government of small Families, the concord whereof dependeth on naturall lust, have no government at all; and live at this day in that brutish manner, as I said before. Howsoever, it may be perceived what manner of life there would be, where there were no common Power to feare; by the manner of life, which men that have formerly lived under a peacefull government, use to degenerate into, in a civill Warre.

But though there had never been any time, wherein particular men were in a condition of warre one against another; yet in all times, Kings, and persons of Soveraigne authority, because of their Independency, are in continuall jealousies, and in the state and posture of Gladiators; having their weapons pointing, and their eyes fixed on one another; that is, their Forts, Garrisons, and Guns upon the Frontiers of their Kingdomes; and continuall Spyes upon their neighbours; which is a posture of War. But because they uphold thereby, the Industry of their Subjects; there does not follow from it, that misery, which accompanies the Liberty of particular men. "

So in order to promote the most peace everyone should be under the same government? The process for doing that is colonization to “civilize” them to be in the same umbrella. I can see why liberals did imperialism and the world wars from this kind of thinking.