Ours is a world of do-gooding, democratic semi-tyranny. When it comes to politics, so long as your motivations are to do good to your fellow man, and so long as your methodology is democratically-approved activity, then you can tyrannize your fellow citizen pretty much without limit. The transcendent social and political values of do-gooding and democracy give you such license.
Slavery is no longer slavery, if the government is trying to benefit its citizens, and this behavior is supported by a majority vote. If you are engaged in service to your brothers, and backed by an act of democracy, then you can brutally fuck over your fellow man essentially to infinity. Any government atrocity and limitless horror inflicted upon millions of innocents is perfectly okay -- indeed, it's quite admirable -- so long as you're being faithfully altruistic and majoritarian.
So destroy and enslave away, do-gooder democrats! You're the good guys!