In recent weeks, attention has focused on two freshman Democratic members of Congress, Ilhan Omar (Minn.) and Rashida Tlaib (Mich.), both of whom are Muslim and have made critical statements about Israel and its most ardent American supporters. Their tweets and comments have been portrayed by some as not simply criticisms of Israel but rather as evidence of a rising tide of anti-Semitism on the new left.

I don’t know what is in the hearts of the two representatives. But I believe that Muslims should be particularly thoughtful when speaking about these issues because anti-Semitism has spread through the Islamic world like a cancer. (Omar and Tlaib are not responsible for this in any way, of course, but they should be aware of this poisonous climate.) In 2014, the Anti-Defamation League did a survey in more than 100 countries of attitudes toward Jews and found that anti-Semitism was twice as common among Muslims than among Christians, though it’s far more prevalent in the Middle East than the Americas. It has sometimes tragically gone beyond feelings, morphing into terror attacks against Jews, even children, in countries such as France.

It might surprise people to know that it wasn’t always this way. In fact, through much of history, the Muslim Middle East was hospitable to Jews when Christian Europe was killing or expelling them.