That, as Bruce Thorton's argues in this interesting and informative article, is the double standard that applies to the West when historical grievances are aired. Thorton's basic point is that, while the grievances of Islam against the West are real, they are outweighed (or are, at least, no worse) than the grievances of the West against Islam.
If history is to provide the foundation of grievance, however, then all of history is on the table, and that history must be factually accurate and judged by consistent standards. If, for example, the enslavement of Africans is an evil for which the West must take responsibility, then all slavery everywhere must be condemned equally. But when do we ever hear about Islamic slavery? In the three-century long heyday of Western slavery, some 10 million slaves crossed theYet we rarely hear Westerners acknowledging those grievances, and we never hear Muslims apologizing for them. Hence, Thorton's point about the systematically applied double standard against the West.
Atlantic. Yet in the 14-century-long existence of Islamic slavery––still going on today in Africain places such as –an equal number of black Africans were enslaved by Muslims. ... Don’t forget that included in the toll of those enslaved by Muslims were millions of Europeans taken in raids and sold for the harems, armies, and galleys of Muslim emirs, sultans, and caliphs. Sudan–
So too with the presumed sins of “colonialism” and “imperialism.” The modern European presence in the Muslim Middle East lasted for less than two centuries. Yet Muslims occupied
for over seven centuries, and the Muslim occupation of the Balkans for half a millennium didn’t finally end until World War I. And vast regions of the Middle East––north Africa, Egypt, Turkey, the Holy Land––that were not Muslim but Christian homelands, are still “occupied” by the descendents of imperialistic, colonizing Muslim Arabs and Turks who came as alien invaders and conquered those territories. Spain
Check the article out. It's well worth reading.