I'm not sure the union and the confederacy saw themselves as separate cultures though? And either way, I'm not convinced that it was an acceptable use of force (granted, it's not a subject I have any great depth of knowledge in). There are parts of the world today where certain members of society live in conditions not far from slavery, and while I very much hope those societies can in time see the advantages of agreeing on and adopting a more free and equal set of human rights, I don't believe it's justified to use force to impose them just because we're so certain of their "unalienable" nature.

> I don't believe it's justified to use force to impose them just because we're so certain of their "unalienable" nature.

I don't recall any slaves that were unhappy that the US went in and freed them.

I would imagine not a few slaves would have been killed in the process! Either way, that on its own doesn't justify the bloodshed that occurred, and arguably the divisions in the US that don't appear to have fully healed yet. And from what I do know about it, I wouldn't say the US civil war was a good example of an unprovoked party forcibly trying to impose their own "rights" on another society anyway.

One thing I'm willing to agree with you on is that the justifications used by those who believed in slavery were "wrong" - they made assumptions about the biological characteristics of people based on their skin colour or country of origin that weren't justified on any scientific or humane basis. There's really no excusing any sort of belief that people who are clearly capable of the full range of human emotions and thought processes were somehow subhuman and not deserving of free man status. Perhaps there's never been an example of slavery in society that wasn't accompanied by such beliefs, and on that basis I'd accept that all existing examples of slavery that I know of, past or present, are "wrong".