Memorial Day seems a fitting time to review the movie “Goodkill,” now playing in theaters around the country. The movie, based on actual events, portrays a morally-conflicted and psychologically-tormented operator of unmanned aerial vehicles (UAVs or “drones”), played by Ethan Hawke. Even though the plot includes some obvious Hollywood enhancements, it presents some basic facts about drone warfare, facts that are little known to the U.S. public. For instance, drone operators accidentally kill civilians, but sometimes see that civilians (including children) are present and proceed (or are ordered to proceed) anyway. “Signature strikes” do not target individually-recognized terrorists, but groups that fit a particular profile.