The Crusades, Christianity and Islam by Jonathan Riley-Smith
Jonathan Simon Christopher Riley-Smith is the author of scores of material regarding the Crusades.
This easy-to-read book is divided into four chapters. The first two present the idea that the Crusades were deeply rooted and justified for polities which claimed adherence to Christianity and the individual Christians who participated. The third chapter described the role of European protocrusader, pseudocrusador rhetoric in 19th century imperialism.
The fourth chapter basically claims that the only reason we view the Crusades as a particularly gruesome, unusual period of history is an anti-religious, anti-imperial period of European intellectual history, particularly after World War I. Muslims, who had hardly noticed the Crusaders, misappropriated this European production for their own nationalistic purposes. This misappropriation culminated in the widespread, erroneous ideas prevalent among Muslims that the West continues its Crusades to this day.
Matthew Gabriele identified one problem with this view, namely that it implies that there was no reason at all for the mid-twentieth century Arab intellectuals to popularize the contemporary view of the Crusades. My other concern is that the author does not actually cite any Muslim or Arab Christian historians to support his view that they promote a distorted view of the Crusades and modern history. The author presents the view of Osama bin Ladin and Ayman al-Zawahiri and Hizb al-Tahrir, which is the equivalent of presenting the rhetoric of the KKK and the John Birch Society and Rush Limbaugh as the pinnacle of the U.S. historiography. Amin Maalouf's The Crusades through Arab Eyes is listed as a source, but it is not discussed in detail. I did not recognize any contemporary Arab historians of the Crusades in the sources list. The author does not list any Turkish or Arabic sources. Finally, I think the author exaggerates when he claims that pre-modern Muslim historians ignored the Crusades. I think it would be worth a look at al-Maqrizi's works to see how serious he regarded the Crusaders. I am no expert, in this or any field :-), and perhaps the publishing requirements limited the author in this regard. In this case, I'd appreciate comments directing me to sources supporting the author's contentions.
A particularly annoying passage relies on Bernard Lewis and Hizb al-Tahrir to maintain that Muslims could not possibly know anything about the Crusades since they were unconcerned with anything non-Muslims did (p. 71).
The author does not address how modern Christian Arabs and Muslims are supposed to regard Christian Zionism and U.S. military religious zeal. If saliibi (modern Arabic for Crusader) is the wrong word, and colonialist and imperialist are out of style since the collapse of communism, then by all means suggest a more accurate term for ongoing Western military intervention.
November 14, 2009 addendum: Check out Abdal-Hakim Murad's article America as a Jihad State: Middle Eastern perceptions of modern American theopolitics. It goes into much more detail about contemporary Muslim notions of Crusaders based on the actions of the Bush Administration and individual U.S. citizens post September 11, 2001.
January 22, 2011 addendum: Check out Seymour Hersh's claim 'that key branches of the U.S. military are being led by Christian fundamentalist "crusaders" who are determined to "turn mosques into cathedrals."'
P.S. I've added some more links in the comments, but I'm adding more here on November 3, 2012: