COMMENT | In the personal realm we have friends who are friends, and often bosom buddies, with people we don’t talk to, don’t respect, strongly distrust, and sometimes who are even our sworn enemies.

But can we insist that they not be friends with our enemies before they are our friends? Surely not. It would lead to an ever-shrinking social circle and isolation from others. We have no right to decide who our friends’ friends are.

For historical, political, strategic, ethnic, and other even less...