I worked as a trauma surgeon in Gaza from March 25 to April 8. I’ve volunteered in Ukraine and Haiti, and I grew up in Flint, Mich. I’ve seen violence and worked in conflict zones. But of the many things that stood out about working in a hospital in Gaza, one got to me: Nearly every day I was there, I saw a new young child who had been shot in the head or the chest, virtually all of whom went on to die. Thirteen in total. At the time, I assumed this had to be the work of a particularly...