“Two things are infinite,” Albert Einstein said. “The universe and human stupidity, and I’m not sure about the universe.”

Einstein could have added a third element in endless supply that is a close cousin of the second: the bottomless pit of artist celebrities who feel anointed because of their success or ego to lead foreign affairs debates.

Roger Waters, the bassist and a lyricist for Pink Floyd, one of rocks’ greatest acts, is a high-profile poster child for Boycott, Divestment and Sanctions (BDS) against Israel, an organization embraced by the European and American left that advocates boycotting Israeli academics, culture, businesses and institutions.

BDS calls the Israeli government as an “apartheid regime.” Far from the mainstream of political thought, the organization doesn’t support a two-state solution with the Palestinians. Its leaders have no time for condemnation of Muslim nations with their gulags and police state apparatus. BDS is bent on Israel not existing as a Jewish state, if at all.

Perhaps Mr. Waters is unaware of the not-so-hidden agenda of the organization and its adherents. After all, it’s been a while since he penned the song “Sheep” in which he sings of people who won’t or can’t think for themselves.

“What do you get for pretending the danger’s not real/

Meek and obedient you follow the leader,” he sings.

And follow the leader is what Mr. Waters has done. He made news when in an open letter in August when he used his pop artist’s platform for renewing BDS’s call on musicians everywhere to boycott Israel.

“Please join me and all our brothers and sisters in global civil society in proclaiming our rejection of Apartheid in Israel and occupied Palestine, by pledging not to perform or exhibit in Israel or accept any award or funding from any institution linked to the government of Israel, until such time as Israel complies with international law and universal principles of human rights,” Waters wrote.

“Occupied Palestine” is longstanding code for the land between the Jordan River and the Mediterranean Sea, in other words, the state of Israel. Even if Mr. Waters didn’t realize what he was saying, his bedfellows certainly did catch its true meaning.

Mr. Waters drew a harsh rebuke from Abe Foxman, National Director of the Anti-Defamation League.

“Your single-minded obsession with trying to convince others to boycott the Jewish state, while ignoring the world’s true human rights violators, must be driven by something other than a guilty conscience,” Foxman wrote.

“Anti-Semitism” as a charge must be judiciously invoked, if for no other reason than it devalues those actual instances. But Mr. Foxman might be on to something.

China oppresses millions. Russia continues on a czarist trajectory. Despotic Arab and Muslim countries for decades have lacked the rule of law, political plurality, and cage and/or murder dissidents while denying women and minorities equal rights (see Egypt, Syria, Sudan, Saudi Arabia, to name a few). Thousands of Syrians and Egyptians are mowed down in the streets, as Christians throughout the Middle East dwindle through murder and forced emigration under threat by the Muslim majority, as Syria commits war crimes by using chemical weapons against its own people.

Several African nations resort to genocidal behavior with alarming regularity. North Korea starves its population, while Iranian leaders call for the annihilation of Israel.

And yet Roger Waters and his colleagues who promote the boycott single out Israel for isolation. This tin ear to the real world parallels the Orwellian politics of the U.N., in which the U.N. Human Rights Council, the globe’s top watchdog for calling out human rights violations, includes many member states with horrific human rights records.

If Mr. Waters and BDS wanted to make a point about supporting “universal principles of human rights,” they should turn their glare to the Muslim world for starters. If Mr. Waters needs inspiration for doing so, he could turn to a number of powerful Pink Floyd songs he wrote in which singling out hypocrisy is a major theme.

Even if the extreme focus on Israel amid the calamity befalling Muslim nations — amid the dearth of human rights around the world — isn’t anti-Semitism, it is certainly curious.

Like Mr. Waters, other artists have ventured into world affairs, often on the wrong side of history and common sense. The gifted filmmaker Leni Riefenstahl was on Hitler’s payroll. Gabriel Garcia Marquez extolled the virtues of a serial human rights abuser, Fidel Castro. Pablo Picasso was an ardent communist and a sometime friend of Moscow in the era of the murderous Stalin, one of the worst mass killers in modern history.

Their lesson for Mr. Waters is that success in the arts usually isn’t a transferable skill and that sometimes, when combined with ego unbound and lack of critical thinking, can make an accomplice of the most well-meaning.

In the Pink Floyd song “Comfortably Numb,” Waters sings a refrain that might be asked of him today:

“Hello, is there anybody in there? Just nod if you can hear me, is there anyone at home?”