BEIRUT, Lebanon — He has been mentor to some of the most brutal terrorists on earth. But Abu Muhammad al-Maqdisi, a prominent cleric and theorist of jihad living in Jordan, has grown tired of hearing younger extremists accuse him of going soft. So in a recent Internet post to his followers, Mr. Maqdisi defended his hard-line credentials by invoking a higher authority: the Combating Terrorism Center at West Point. "Credit is due to the testimony of enemies," Mr. Maqdisi wrote, as he directed his readers to a recent journal article by Joas Wagemakers, a Dutch scholar of jihadism, and the "Militant Ideology Atlas," both published by the center. Both identified Mr. Maqdisi as a dangerous and influential jihadi theorist, he noted. So did two articles by liberal Arab columnists, Mr. Maqdisi added proudly, including one that referred to him as a "sheik of violence" and "the head of the snake." It is not new for Islamic extremists to cite Western counterterrorism reports. Ayman Zawahri, the deputy of Osama bin Laden, has referred at least twice in his taped statements to "Stealing Al Qaeda's Playbook," a 2004 article also published by the center. But recently Mr. Maqdisi has taken this hall-of-mirrors phenomenon to a new level, complaining bitterly that secular Western analysts generally understand him better than many in his own community. "I am surprised at the low level of their thinking," Mr. Maqdisi wrote of his critics, "and how the enemies of religion read and understand us better than they do." The complaint is a testament to the growing community of Western jihad watchers, an obsessive and multilingual crew who monitor and debate terrorist Web statements like Talmudic scholars poring over a manuscript. It also illustrates the fragmentation of authority within the global jihadist movement, where even prominent figures like Mr. Maqdisi are vulnerable to younger critics who feel free to interpret the call to jihad, and the Koran generally, as they see fit. For the Western analysts, being cited approvingly by a Qaeda figure can be unsettling. "It is inevitably a little bit flattering," said Thomas Hegghammer, a fellow at Harvard's John F. Kennedy School of Government, who first pointed out Mr. Maqdisi's complaint on the blog he edits, Jihadica. "But it does make me worry a bit about the implications of what I do and what I write." The home page of the Jihadica site, founded a year ago by the scholar William F. McCants, advertises itself with an anonymous quotation said to be taken from a survey of jihadists about Internet sites that monitor militant Islamism online: "It is, in my view, the most important and dangerous among the sites in this group." All this self-consciousness is multiplied by the Internet, which has become a recruiting tool for jihadists but is also uniquely vulnerable to spies and informers. The fact that Western scholars and defense analysts have occasionally proposed using influential theorists like Mr. Maqdisi to undermine jihadist movements only makes this worse. For all their suspicion toward each other, many militant Islamists often speak of Western analysts — especially those with a clear link to the military — with the respect due a true enemy. Mr. Maqdisi, whose Web site includes the world's largest online compilation of jihadist literature (it is searchable by author), is clearly aware of what is written about him, and about jihad generally. Despite his stature, he has been fighting off criticism from jihadists for years. Born in what is now the West Bank, Mr. Maqdisi spent time in Pakistan and Afghanistan in the 1980s, where his writings and speeches legitimizing violence influenced Osama bin Laden and others. In the mid-1990s he was sent to prison in Jordan and became the spiritual mentor of a fellow prisoner, Abu Musab al-Zarqawi, who later became notorious for decapitating hostages as the leader of Al Qaeda in Mesopotamia. In 2005 Mr. Maqdisi was briefly released from prison and criticized Mr. Zarqawi's bloody car-bombing campaign against the Shiites of Iraq. That led some to accuse him of becoming a tool for the Jordanian or American authorities, an accusation that has been renewed in recent months. Mr. Maqdisi, who is now under house arrest in Jordan, has angrily turned that accusation against his critics, arguing that their efforts to undermine him and other jihadist leaders derive from a strategy outlined by Western analysts working for "the Crusader RAND Corporation." In fact, at least a few Islamists seem to see the hand of the RAND Corporation, an American policy organization that produces reports on terrorism and other subjects, in many plots. This year a hard-line Saudi cleric told this reporter during an interview that "RAND-ites" were seeking to de-Islamize Saudi Arabia. Mr. Maqdisi's problem is more homegrown. A new generation of jihadists, many of them less educated and respectful of authority than their elders, has begun taking issue with him. Mr. Maqdisi believes suicide bombing is a legitimate tactic but has said it should not be used indiscriminately, and he has spoken against the sectarian massacres in Iraq. For this he is accused of turning his back on jihad. In a sense, Mr. Maqdisi can hardly complain, because he did the same thing to his clerical elders when he was young. "For several decades, there has been a dynamic at work in the radical Sunni Islamist community where each new generation becomes less principled, less learned, more radical, and more violent than the one before it," said Bernard Haykel, a professor of Middle East studies at Princeton. In fact, recently some Western counterterrorism experts have seized on this trend and hailed it as proof that Al Qaeda and its affiliates are doomed to destroy themselves in an orgy of violence and in-fighting. Whether Mr. Maqdisi will also cite those Western theories in defense of his own approach remains to be seen.