It's hard to keep up with all of the outrageous things Trump says, but one statement of his that continues to get bad press is this: "The other thing with the terrorists is you have to take out their families, when you get these terrorists, you have to take out their families. They care about their lives, don't kid yourself. When they say they don't care about their lives, you have to take out their families."
That's been widely denounced. However, it's an example of how critics fail to adequately address Trump's "solutions". Problem is, many supporters probably like what he said. To merely express disapproval simply reinforces their impression that Trump's critics are soft. Trump is prepared to do what's necessary. He will protect us. By contrast, his critics are paralyzed by political correctness.
i) On the face of it, there's a certain logic to what he said. If you wish to deter terrorists, you attack something they care about. Even if a terrorist is prepared to sacrifice his own life for the cause, he will balk at exposing his family to harm. Therefore, you have to hit them where it hurts. So what, exactly, was wrong with Trump's statement?
ii) To begin with, even if that was an effective tactic, military ethics is very important. In a way, ethics is even more important in warfare because the stakes are so much higher. There's a much greater potential or temptation to commit atrocities. Especially in war, we need to draw certain lines.
iii) Apropos (ii), this isn't just airy-fairy idealism. What makes us better than the enemy? What gives us the moral justification to wage war? If we're prepared to do whatever the enemy does, then we're all villains.
iv) What does he mean by their families? There's a sense in which terrorism can be a family business. You can have fathers, grown sons, and adult brothers who are terrorists. Family in that sense is fair game. But if Trump means women and underage children, that's a different issue.
v) Over and above the ethical concerns are logistical issues. Who, exactly, does he have in mind? Does American intelligence have a list of names and addresses for every terrorist family, or even most terrorist families? Presumably, we can't just send a cruise missile or predator drone to the address of every terrorist family, because we don't know where most of them reside. At best, I presume we only know who the leaders are. The upper echelon of terrorist networks. But even in that case, that doesn't mean we know their whereabouts.
vi) If you can't perform surgical strikes to take out the terrorists, then the alternative would seem to be carpet bombing. Kill everyone within a certain radius to make sure you get the terrorists. That gives you a margin.
Here's a problem with that tactic: one justification for defeating ISIS is to protect innocent civilians from ISIS. This is, in part, a humanitarian mission. But unless ISIS members are segregated from the general population, then Trump's proposal is like "destroying the village to save the village".