Slavery and genocide are ancient bedfellows. I first became aware of this fact as a child while watching the opening number of DreamWorks’s 1998 film, The Prince of Egypt. In the first five minutes of the movie, enslaved Hebrew men construct monuments to the Pharaoh as their wives beg for their infant sons’ lives. All, save Moses, are ripped from their mothers’ arms and tossed into the Nile.Of course, with 21st-century technology, crocodile-infested rivers are no longer needed to get rid of minority children. We have “medicine” for that.Last week, drone footage, verified by Western intelligence agencies, emerged from Northern China. It showed Uighur Muslims bound and blindfolded, with shaven heads, being loaded onto trains that were likely headed for detention camps. In a BBC interview, British journalist Andrew Marr demanded answers from Liu Xiaoming, the Chinese ambassador to the United Kingdom. Xiaoming accused “so-called Western intelligence agencies” of making “false accusations a...