The Washington Post published a disturbing report Friday evening, detailing the deadly Aug. 10 attack on Marines at Forward Operating Base Delhi in the Garmser district of Afghanistan’s Helmand province. Among the revelations, according to reporter Kevin Sieff’s story: These killings were carried out, allegedly, by a 15-year-old Afghan boy — described as a personal assistant to the district police chief, who’s been accused of having an affinity for young boys and abusing them. Moreover, Sieff’s report contends the boy lived on the base but was never put through the coalition’s rigorous vetting process used for all members of the…