Since the European migrant crisis began, no news photo has given the advocates of more humane border policies hope than the widely circulated picture of the three-year-old Syrian boy, Aylan Kurdi, lying dead on a Turkish beach after drowning at sea.

As he lies on the shore in his red shirt and black shorts, Aylan looks as if he might be taking a nap. His death is a horrifying reminder of what happens when migrants from the Middle East and Africa can’t get the help they need to rebegin their lives.

But as the controversy surrounding Aylan’s death continues, we need to be aware of the limited power of images to change government policy. As a number of commentators have pointed out, a photo taken during the Vietnam War offers a striking comparison with last week’s photo of Aylan.

That photo is the one AP photographer Huynh Cong “Nick” Ut took on June 8, 1972 of nine-year-old Kim Phuc running from a napalm attack on her Vietnamese village that was ordered by an American commander.

In the Pulitzer Prize-winning picture, which was first known as “napalm girl” and appeared in Newsweek, Phuc is completely naked. Her clothes have been burned off her. Her arms are outstretched. Her mouth is open as she screams in terror. ...