All of Islam…

to punish groups that carry out terrorist attacks. There’s no question that some such groups have grown out of the Muslim Brotherhood, like Hamas, the adversary of Israel, which the United States named a terrorist organization in 1997. Egypt’s president, Abdel Fattah el-Sisi, has worked to crush the Brotherhood in his country since he overthrew his predecessor, Mohamed Morsi, a former Brotherhood leader, in 2013. But there is no evidence that senior Brotherhood leaders ordered any violence or carried out any of the recent major terrorist attacks in Egypt, according to the analysts Michele Dunne and Nathan Brown of the Carnegie Endowment for International Peace.

But those advising Mr. Trump seem unwilling to draw distinctions. Stephen Bannon, the chief White House strategist, once called the Brotherhood “the foundation of modern terrorism.” And Frank Gaffney Jr., an anti-Muslim analyst who heads a small think tank, recently told The Times that the Brotherhood’s goals are “exactly the same” as those of the Islamic State and Al Qaeda.

It is wrongheaded and dangerous to tar all Brotherhood members with one brush. The Brotherhood is associated with political parties in Indonesia, Pakistan, Morocco, Jordan, Iraq, Kuwait, Yemen and even Israel, and runs schools and hospitals. Many of those parties are America’s partners. The governing party in Turkey, a NATO member, also has connections to the Brotherhood. If the group is named to the terrorism list, how will Washington continue these relationships without violating the law?

Another risk is that penalizing people and countries that deal with the Brotherhood could make it impossible for members to continue their involvement in politics and even push some of them into violence.

Mr. Trump made America look cruel and incompetent in the eyes of the world with his sweeping immigration edict. Now talk of branding the Brotherhood as a terrorist group has fueled darker fears of an administration intent on going after not just terrorists but Islam itself.