During World War II, the leader of the Palestinians lived in a Berlin villa, a gift from a very grateful Adolf Hitler, who clearly got his money's worth. Haj Amin al-Husseini, the grand mufti of Jerusalem and as such the titular leader of Muslim Palestinians, broadcast Nazi propaganda to the Middle East, recruited European Muslims for the SS, exulted in the Holocaust and after the war went on to represent his people in the Arab League. He died somewhat ignored but never repudiated.

Husseini might have been a Nazi to his very soul, but he was also a Palestinian nationalist with genuine support among his own people. The Allies originally considered him a war criminal, but to many Arabs, he was just a patriot. His exterminationist anti-Semitism was considered neither overly repugnant nor all that exceptional. The Arab world is saturated by Jew-hatred.

Some of this hatred was planted by Husseini and some of it long existed, but whatever the case, it remains a remarkable, if unremarked, feature of Arab nationalism. The other day, for instance, about 1 million Egyptians in Tahrir Square heard from Sheikh Yusuf al-Qaradawi, an esteemed religious leader and Muslim Brotherhood figure whose anti-Semitic credentials are unimpeachable. Among other things, he has said that Hitler was sent by Allah as "divine punishment" for the Jews. His al-Jazeera program is one of that TV network's most popular.

I have read the assurances of scholars and journalists alike that the Muslim Brotherhood has mutated into the Common Cause of Egypt (Jordan, too) and that its anti-Semitism is merely an odd and archaic quirk, like the anti-fluoride positions of some American conservatives. I hope this is the case. But in truth, I put more faith in the staying power of anti-Semitism than I do in the forecasting gifts of my colleagues. If they are right, wonderful. If not, we all have something to worry about.

The trouble with democracies is that they tend to cater to the prejudices of the people - not just to their good sense. This explains why almost all the nations of Central and Eastern Europe turned rabidly anti-Semitic when democracy was instituted after World War I. Anti-Semitism was a popular sentiment and it was exploited by unprincipled politicians. The result in Poland, for instance, was the stated policy of declaring the Jews - about 10 percent of the country - personae non gratae. By then, they had been in Poland for only about 1,000 years.

There are nearly no Jews in Arab lands - they were kicked out after Israel was established in 1948. Nowhere in the Middle East is peace with Israel popular. Nowhere in the Middle East is anti-Semitism considered aberrant or weird. It is inconceivable to me that Arab politicians will not attempt to harness both sentiments, combining nationalism with anti-Semitism - a combustible and unstable compound. History instructs about what follows.

Israeli leaders are well aware that they face a new reality in their region. Whatever regime arises in Egypt, it is likely to chill even further what is already called a cold peace. The same might hold for Jordan. King Abdullah is secure for now - the Bedouin tribes need him to avoid chaos - but he, too, will have to listen to popular sentiment.

Consequently, now would be the propitious time for Israel to settle with the Palestinians. I am aware that resolution of the Palestinian issue will not satisfy anti-Semites or extreme Arab nationalists - Israel is not going to give up all of Jerusalem nor, for that matter, disappear - and both Hezbollah in Lebanon and Hamas in Gaza have only been emboldened by recent events. Still, the creation of a Palestinian state - the lifting of all the onerous restrictions on Palestinian movement - will take some air out of this particular balloon and, possibly, improve Israel's deteriorating moral standing in Europe and elsewhere. This is no small matter.

Israel's critics have a case. Yet they make no case when it comes to Arab anti-Semitism. The prominence of Qaradawi cannot be reassuring to Israelis. They know that words can be weapons and hate is a killer. Nonetheless, since the days of Husseini, a true Hitlerian figure, Arab nations have shamefully been granted an exception to the standards expected of the rest of the world, as if they were children. If I were an Israeli, I'd be worried. If I were an Arab, I'd be insulted. If I were a critic only of Israel, I'd be ashamed.

cohenr@washpost.com