The burning image of World Trade Tower had made itself becoming the defining moment of the new 21st century. Among numerous possible causes of the incidence, many Americans heavily criticized the nation's inability to collect indications and warnings of the attack beforehand. However, the intelligence failure actually lies in several lapses in CIA and FBI operation and collaboration.
The first mistake that FBI and CIA stumbled is that both agencies overlooked the indications that forewarned the 9/11 and underrated importance of the counter-terrorism at that time. Looking back to the years preceding 2001, in 1998, Al Qaeda's troops had threatened that they were ready to kill American at anywhere in the world and ,in 2000, the US National Commission on Terrorism (NCT) also tried to show the American government that a further terrorist attack on the United States was not impossible. Warnings from Federal Aviation Administration were also sent to FBI that 'Muslims are aimed at hijacking aircrafts and commercial airplanes'. However, despite those premonitions, counter-terrorism was not pritoritised: The attorney general at the time, John Ashcroft, had a focus on guns and drugs. Also the FBI was focused on public corruption, organized crime, major white-collar crimes, not the Muslims attack.
The second mistake that contribute to the terrorist attack was failure of communication between FBI and CIA. It is clear that while FBI is inclined towards solving national and domestic crimes that infiltrate the Federal Laws, CIA focuses on protecting the national security against external forces. Despite differences in methods and aims, informants from both Intelligence Agency did possess parts of valuable information that could have prevented the accident. Two years before the attack, CIA was informed about the interaction between two Muslim men, Khalid al-Midhar and Nawaq Alhazmi, both of whom were under the control of FBI. Had CIA informed FBI about the connection between two men, FBI could have inactivated the plan from the beginning. Clearly, both sides seem to have collected some pieces of puzzle of their own, but refused, or at least reluctantly revealed, to talk with each other to finish the big picture.
Although the accident has already been something of the past, I still want to propose possible changes that can prevent the 11th September from happening. First, there should have been a forum for shared information between two agencies on prioritised topic like terrorism, cyber attack, nuclear missiles, etc. Also, a clearer definition that distinguish each agency's responsibility is necessary. Like in the case of 9/11, while CIA is better at collecting information worldwide, FBI has its right to investigate and control any Americans if evidence is provided. This distinction is often misunderstood between both sides, mistaking that the other side has been in charge of this task (while actually no side did it). Last but not least, jealousy among the intelligence community is inevitable. But it is vital for both agencies to work rationally, not emotionally, for the sake of every innocent American life.