On the differences between anti-Zionism and anti-semitism

Jeffrey Goldberg quotes a Soviet-era joke from one of his readers:

A prominent scientist is being summoned to his institute's party secretary.

"Comrade professor", says the secretary gravely, "the Party has started a new anti-Zionist campaign. Our institute was ordered to purge all residual Zionist influences among intellectuals and scientists. So, you're fired."

The professor is shocked. "But I am a loyal party member!"' he protests. "I have never been a Zionist!"

The party secretary knits his eyebrows very tight. "Comrade professor, do not try to deceive the party!" he says. "We checked. You have a Zionist grandmother."