On September 11, 2001, American history was forever changed when nineteen Middle Eastern hijackers commandeered four commercial airplanes. Two of the planes were flown directly into New York City’s World Trade Center, causing the Twin Towers to collapse and creating massive casualties; a third plane was flown into the Pentagon, leading to significant structural damage and additional injuries and fatalities; the final jet crashed into a Pennsylvania field following a struggle between the passengers and hijackers. All told, more than three thousand people died in a seemingly unimaginable act of terrorism. The attacks were soon linked to terrorist plotter Osama bin Laden and the al-Qaeda terrorist network. At first the events of September 11 seemed to be something that no one could have predicted; not once in the previous history of hijacking had assailants flown planes into buildings. Gradually, however, Americans learned that U.S. intelligence agencies had known prior to September 2001 that such a terrorist attack was possible; unfortunately, the FBI’s and CIA’s information was incomplete, and neither agency took action that might have helped prevent the tragedy. The discovery that the attacks might have been prevented sparked widespread discussion as to why America’s intelligence agencies failed so tragically. The first problem faced by intelligence agencies was their inability to gather critical information on known terrorists. In December 2002 the Senate Select Committee on Intelligence and the House Permanent Select Committee on Intelligence issued the results of a joint inquiry into the events of September 11. In their report the committees concluded that the intelligence community knew by the summer of 2001 that bin Laden and al-Qaeda were plotting an imminent attack “against U.S. interests.” However, the committees as15 serted, “Prior to September 11, 2001, the Intelligence Community did not effectively develop and use human sources to penetrate the al-Qa’ida inner circle. This lack of reliable and knowledgeable human sources significantly limited the Community’s ability to acquire intelligence that could be acted upon before the September 11 attacks.” Of the factors that have been identified to explain the failure of American intelligence agencies to successfully infiltrate al-Qaeda, one that has received particular attention is the lack of agents who could speak or write Arabic. Prior to September 2001, only twenty-one FBI agents knew Arabic, according to the congressional report. The consequences of this limited knowledge of Arabic are serious, as former CIA inspector general Frederick A. Hitz explains. He writes, “As difficult as it may be to recruit an informant in a terrorist cell of individuals willing to expend their lives in suicide missions, it’s impossible if you don’t speak or read the language and understand the culture from which they come.” A greater problem, however, is that not only did the CIA and FBI lack the ability to infiltrate terrorist cells, but when agents uncovered information about potential terrorists, their findings were often ignored. In two separate cases that occurred during the summer of 2001, FBI agents learned about men who were suspected of being Islamic terrorists enrolling in flight schools. When Bill Kurtz, a supervisor at the FBI’s Phoenix office, and his team of agents—in particular counterterrorism agent Kenneth Williams—made such a discovery in July 2001, they sent a memo to FBI headquarters urging the monitoring of flight schools throughout the country. The memo was ignored. In August 2001 the FBI office in Minneapolis found that Zacarias Moussaoui, a foreign-born student at the Pan Am Flight Academy in Eagan, Minnesota, was learning to fly a Boeing 747. The employee from the flight academy who contacted the FBI was particularly concerned because Moussaoui was interested only in flying the plane once it was in the air, not in learning how to take off or land. Suspecting that Moussaoui was a potential hijacker, FBI investigators attempted to get a warrant to search his computer but were refused because there was no “probable cause” that the man had committed a crime. Moussaoui was later discovered to have ties to al-Qaeda and the September 11 plot. Another reason why key intelligence information was not always acted upon was “the Wall,” the name given to guidelines issued in 1995 that governed contacts between FBI agents working on different terrorism cases. As explained by Heather MacDonald, a contributing editor to City Journal, the Wall made it nearly impossible for agents to share information that could have strengthened each others’ investigations because any exchange of information first had to be approved by FBI headquarters. The problem, as MacDonald explains, is that the Washington office would not “have the ground-level knowledge necessary to understand the potential significance to each investigator of [the information].” In light of these intelligence failures, intelligence agencies have developed more effective ways to discover and prevent future acts of terrorism. The FBI has nearly doubled the number of counterterrorism agents since September 2001, from thirteen hundred to twenty-five hundred, and hired more than one hundred Arabic-speaking linguists. The CIA has also hired more agents and has had its budget increased by several billion dollars. The FBI and CIA have also coordinated their efforts through daily meetings between their directors and have created the Terrorist Threat Integration Center, a partnership between the FBI, CIA, Department of Homeland Security, and other related agencies that will improve communication within the intelligence community. The attacks of September 11, 2001, proved that not even the world’s lone superpower can protect itself against all enemies. However, changes in the FBI and CIA may help prevent some acts of terrorism; in fact, since September 2001, more than one hundred potential acts have been thwarted. In Opposing Viewpoints: Terrorism, the authors debate some of the issues surrounding terrorism in the following chapters: Is Terrorism a Serious Threat? What Are the Causes of Terrorism? How Should America’s Domestic War on Terrorism Be Conducted? How Should the International Community Respond to Terrorism? While terrorism may never be completely eradicated, the United States must not allow the intelligence failures of the past to permit a repeat of September 11.