In laws and in morals, it is wrong for me to hit you, steal your stuff or enslave you. This is nearly a universal truth, held by almost all societies, at almost all periods in human history.
Similarly, if I and a bunch of my friends decide to beat you up, steal your stuff or enslave you, this is still wrong. Again, this is nearly universally held to be true.
If my friends and I form a corporation and beat you up, steal your stuff and enslave you, this would still be wrong, etc.
Now comes the magic.
If my friends and I form an association, and call it a state, then we can take your property, via taxation, civil forfeiture and eminent domain, put you in prison for smoking the wrong plant or loving a person of the wrong sex, or for employing someone for the wrong wage, and put a rifle in your hand and force you off to fight and die in some jungle on the other side of the planet.
Why is this not universally held to be wrong? It is a curious thing.
Libertarians are those who are suspicious of the mechanism that takes a bundle of clearly immoral acts — violence, theft and slavery — and turns them into patriotic virtues. They scrutinize and delineate the conditions (if any) under which collective coercion is legitimate. At the same time they celebrate and seek to push the boundaries of what can be accomplished by free men acting in voluntary, non-coerced associations.