The decision by the Islamic Society of Boston to drop its lawsuit against 17 defendants, including counterterrorism specialist Steven Emerson, gives reason to step back to consider radical Islam’s legal ambitions.

The lawsuit came about because, soon after ground was broken in November 2002 for the ISB’s $22 million Islamic center, the press and several nonprofits began asking questions about three main topics: why the ISB paid the city of Boston less than half the appraised value of the land it acquired; why a city of Boston employee, who is also an ISB board member, fund raised on the Boston taxpayers’ tab for the center while traveling in the Middle East, and the ISB’s connections to radical Islam.

Under this barrage of criticism, the ISB in May 2005 turned the tables on its critics with a lawsuit accusing them of defamation and conspiring to violate its civil rights through “a concerted, well-coordinated effort to deprive the Plaintiffs … of their basic rights of free association and the free exercise of religion.”

For two long years, the lawsuit roiled Bostonians, and Jewish-Muslim relations in particular. The discovery process, while disclosing that the defendants had engaged in routine newsgathering and political disputation, and had nothing to hide, uncovered the plaintiff ‘s record of extremism and deception. Newly aware of its own vulnerabilities, the ISB on May 29 withdrew its lawsuit with its many complaints about “false statements,” and it did so without getting a dime.

Why should this dispute matter to anyone beyond the litigants?

The Islamist movement has two wings, one violent and one lawful, which operate apart but often reinforce each other. Their effective coordination was on display in Britain last August, when the Islamist establishment seized on the Heathrow airport plot to destroy planes over the Atlantic Ocean as an opening for it to press the Blair government for changes in policy.

A similar one-two punch stifles the open discussion of Muhammad, the Koran, Islam, and Muslims. Violence causing hundreds of deaths erupted against “The Satanic Verses,” the Danish cartoons, and Pope Benedict XVI, creating a climate of fear that adds muscle to lawsuits such as the ISB’s. As Mr. Emerson noted when the Muslim Public Affairs Council recently threatened to sue him for supposed false statements, “Legal action has become a mainstay of radical Islamist organizations seeking to intimidate and silence their critics.” Such lawsuits, including the ISB’s, are often predatory, filed without serious expectations of winning but initiated to bankrupt, distract, intimidate, and demoralize defendants. Such plaintiffs seek less to win than to wear down the researchers and analysts who, even when they win, pay heavily in time and money. Two examples:

• Khalid bin Mahfouz v. Rachel Ehrenfeld: Ms. Ehrenfeld wrote that Mr. bin Mahfouz had financial links to Al Qaeda and Hamas. He sued her in January 2004 in a plaintiff-friendly British court. He won by default and was awarded £30,000 (nearly $60,000 today) and an apology.

• Iqbal Unus v. Rita Katz: After Mr. Unus’s house was searched in the course of an American government operation, code-named Green Quest, he sued Ms. Katz, a nongovernmental counterterrorist expert, charging in March 2004 that she was responsible for the raid. Mr. Unus lost and had to pay Ms. Katz’s court costs.

The Council on American-Islamic Relations began a burst of litigiousness in 2003 and announced ambitious fund-raising goals for this effort. But the collapse of three lawsuits, in particular the one against Andrew Whitehead of Anti-CAIR, seems by April 2006 to have prompted a reconsideration. Frustrated in the courtroom, one CAIR staffer consoled himself that “education is superior to litigation.”

This retreat notwithstanding, Islamists clearly hope, as Douglas Farah notes, that lawsuits will cause researchers and analysts to “get tired of the cost and the hassle and simply shut up.” Just last month, KinderUSA sued a specialist on terrorist funding, Matthew Levitt, and two organizations for his assertion that KinderUSA funds Hamas. One must assume that Islamists are planning future legal ordeals for their critics.

Mr. Pipes is the director of the Middle East Forum.