An expert scholar on the Islamic Middle East is Bernard Lewis. In a "specialised sense" he defined antisemitism as:
that special and peculiar hatred of Jews, which has its origins in the role assigned to Jews in certain Christian writings and beliefs concerning the genesis of their faith, and which has found modern expressions in such works as the Protocols and similar portrayals of a universal Jewish plot against both God and mankind.
anti-Semitism did not exist in the traditional Islamic world. True, Muslim religious and other literature provide ample evidence of prejudice against Jews, and Muslim history records not a few cases of persecution. But - and this is surely the crucial point - these attitudes and these persecutions were not accompanied by the demonological beliefs and conspiratorial fantasies that are characteristic of Christian anti-Semitism in both medieval and modern Europe, and do not differ significantly from the hostility and persecution to which other religious minorities, besides the Jews, have been from time to time subject.
Noting that the Qur'an shows greater hostility to Jews than to Christians he states that nevertheless:
the Muslim law makes no such distinction, but treats both subject religions on a footing of equality with each other. In practice, in medieval and in Ottoman times, Jews often fared rather better than Christians, for the obvious reason that unlike their Christian compatriots, they were not suspected of treasonable sympathies with the Christian enemies of the Islamic empires.
The conservative commentator Daniel Pipes concurs with these point from Lewis. Both Pipes and Lewis also agree that things changed in the 19th century when the Muslim world started to employ antisemitic imagery and themes more common in Europe. This more familiar style of antisemitism was imported into the Middle East from Christian Europeans to Christian Arabs and did not originate from Islamic sources. In effect, Muslims began to ape the antisemitism of European Christians.
Robert Wistrich, a noted expert on antisemitism, wrote a very interesting paper in 2002 for the American Jewish Committee entitled, Muslim Anti-Semitism: A Clear and Present Danger. He provides examples where Jews are depicted as the enemies of Islam in the Qur'an but notes that in practice, Jews, like Christians, were afforded the status of dhimmis (“protected peoples.”) Whilst Jews had to pay a jîzya (poll tax) they were accepted as ahl al-kitab (“peoples of the Book”) and were allowed to practice their faith. Whilst Jews were discriminated against by being dhimmis, it is important to realise that this discrimination was not specifically anti-Jewish, as Christians suffered similiarly. Quoting the work of someone else, Wistrich states:
Dhimmis were often considered impure and had to be segregated from the Muslim community. Entry into holy Muslim towns, mosques, public baths, as well as certain streets was forbidden them. Their turbans—when they were permitted to wear them—their costumes, belts, shoes, the appearance of their wives and their servants had to be different from those of Muslims in order to distinguish and humiliate them; for the dhimmis could never be allowed to forget that they were inferior beings.
This is not to say that there were never incidents of violent antisemitism in the Muslim world. As Efraim Karsh points out in his study published two years ago:
The last and most powerful Jewish tribe – Quraiza – suffered more profusely following the abortive Meccan siege of Medina in the spring of 627. Charged with collaboration with the enemy, the tribe’s 600–800 men were brought in small groups to trenches dug the previous day, seated on the edge, then beheaded one by one and thrown in. The women and children were sold into slavery and the money they fetched, together with the proceeds from the tribe’s possessions, was divided among the Muslims. This process was completed on Muhammad’s deathbed in the form of an injunction ordering the expulsion of Jews (and Christians) from the peninsula: ‘Two faiths will not live together in the land of the Arabs’
The relevant issue is that Muslims took (and still take), in the words of Daniel Pipes, "a somewhat patronizing view of other religions." As he states:
A Muslim believes so confidently in the perfection of Islam that he cannot quite comprehend why Jews and Christians continue to follow their outmoded and imperfect versions of the truth.
All these scholars note that Muslim antisemitism became rife in the 20th century. As a phenomenon, it has clearly exploded post 9/11, but this does not mean to say that antisemitism per se is traditionally Islamic. It would be far more accurate to argue that opposition to all other religions has been a fundamental theme in Islamic history.