On US Seal Team 6's killing civilians in the raid on Yemen, 28 January 2017:

         * It was alleged on the National Public Radio Show 1A International, Friday, 3 Feb. 2017, that one or more of the women killed in the fire-fight picked up a weapon and fired back, hence becoming a combatant. The reporter who mentioned that had been embedded with US troops in raids. If the unit he was with had been attacked and he picked up the weapon of a dead combatant, he would become a combatant and could not only be shot in a fire-fight but would be likely to be executed afterward if he were taken prisoner or, if lucky, held as an unauthorized enemy combatant. 

         * The very large context is that holding civilians off-limits for killing is a norm that comes and goes, The point of much medieval raiding was to murder the serfs of an opposing lord, thereby cutting off a source of the enemy lord's income. And it was perfectly proper for much of history to treat as the victor wished the survivors of a town that had resisted, was besieged, and then successfully stormed — to say nothing of the point of a siege of reducing a population to starvation and despair. More recently, the area bombing of World War II was obviously going to kill off a large number of civilians, as was the carpet bombing by the US in Vietnam (etc.). Drones and relatively "smart" munitions are a kind of progress for targeted homicide, except insofar as their greater accuracy is a temptation to use them where just blowing the hell out of someplace with "dumb" munitions would be too obvious a PR loss (not to mention moral issues).

          * One difference between civilian deaths with drone strikes (etc.) under President Obama and with President Donald Trump is that Mr. Trump is on record approving of killing the families of (alleged) terrorists. When a raid occurs where family members are killed, a not-necessarily-correct but legitimate inference is that those who accused Mr. Trump of running a misleading campaign for US President owe him at least one apology: this is a campaign promise he's kept. And those of us who place conscious evil above the banal kind should condemn less the conscious killing of women and children to a casual acceptance of "collateral damage." 
                     (In Dante's Inferno, the "Trimmers" who were neither good nor evil but just for themselves and "blew with the wind" don't make it into Hell proper "For the wicked would have some glory over them" — since the wicked at least chose. The principle applies to those who euphemize killing non-combatants and obfuscate that choosing to drop high explosives in an area with civilians is a decision to kill/risk killing civilians. Also, if you celebrate your side's intentionally killing young men on their side and revel in body-counts, don't get too vocal about unintended killing of old people, women, and children: that's sentimentality, not ethics — or Machiavellian propaganda.)