In fact, within human relations, there is an economic force that is beyond defiance: Cost/benefits. If the benefits of slavery exceed its costs, slavery will exist. Period.
Period.
There is no fighting it, if that dismal formula says otherwise. This is something I have said to people in real life: We will have slavery again the very instant the laws of economics require it. In Haiti it is already so. In Eastern Europe it has been off-and-on (mail-order brides). In America, we will see it yet....