I guess the idea is to create a disincentive for illegal immigration.  But why just take the children?  Why not shoot at least one in front of the parents and other parents?  Swiftian satire will soon be unable to keep up with Trump.  In any case the border patrol officers involved in this should, as a matter of conscience, refuse to comply with these orders.  Full stop.  If you've got the stomach for it, here's a television account.