Bernard Lewis's The Crisis of Islam is essentially a compendium of Islamic history and politics. It is also an attempt at explaining to a Western audience how the Middle East perceives the West. The occasion of its writing (the 9/11 attacks) supports the book's purpose as a document to illuminate "the other" (non-Western, non-Oriental) culture whose extremists were behind this attack.

While the Gulf War, for example, was an effort to free Kuwait and protect Saudi Arabia from Iraqi aggression, Iraq saw this as American aggression. Figures such as Osama bin Laden interpreted American behavior as not only antagonistic to Iraq, but also as targeting Islam. This rhetoric made the West seem inimical specifically to the Prophet (Mohammed), and such an affront Muslims were hardly willing to tolerate.

Lewis takes care to highlight specifically the differences between Islam and Christianity. First, religion is entirely pervasive in Islamic states. There is little distinction between clerical and lay life. He also sheds light on both Islamic cultural and economic circumstances. To some extent (though not entirely), the Islamic state is a theocracy. Lewis explains that Islam after the Islamic Revolution saw the rise of fundamentalist sects that identified America as not only enemy of Islamic nations, but the enemy of God.

Oil was the original cause of consistent interactions between the oil-rich Arab countries and the West. Contemptible Western economic practices and (in many Arabs' view) questionable moral behavior reinforced the stranglehold with which Saudi Arabia treated its resources as well as strengthened Islamic fundamentalism. This process was cemented when the expedient Wahhabi brand of Sunni Islam was endorsed by the Kingdom of Saudi Arabia.

Lewis perspicaciously discusses how jihad has been co-opted in popular opinion by extremists, who cite the Qur'anic justification of terrorism, when in fact the concept is much broader and can be understanding as a "moral striving" rather than simply "war." Lewis also addresses the incontrovertible (though not readily admitted) fact that the Islamic states feel marginalized and discriminated against by the West. Essentially (as demonstrated in a letter allegedly authored by Osama bin Laden) to America, the Islamic world has always sought recognition and respect. In this way, Islam is not much different from Christianity and Judaism, with perhaps the exception that certain (extremist) Muslims will not be so quick to turn the other cheek in the face of oppression.