TWENTY-FIVE years after the planes struck America, the most frightening part of 9/11 may not be what the terrorists achieved, but what they originally intended to achieve – and what intelligence agencies have since learned to prevent. Twenty-five years ago, the world watched in disbelief as four commercial aircraft became weapons of mass destruction. Two disappeared into the towers of the World Trade Centre. Another tore into the Pentagon.
The fourth came down in a Pennsylvania field after its passengers fought back. Nearly 3,000 people died. But that was not the end of the story. In some ways, it was not even the most frightening part. Because the 9/11 that happened was, in important respects, a reduced version of the 9/11 that Khalid Sheikh Mohammed (KSM) and his associates had imagined. Evil reigned in their hearts.
The plot was much bigger
When Vanguard wrote about 9/11 fifteen years ago, to mark the tenth anniversary, what was most fascinating was the audacity of the original conspiracy. The 9/11 Commission documented how KSM’s thinking had evolved from the earlier Bojinka Plot, in which his nephew, Ramzi Yousef, and others had contemplated the destruction of multiple aircraft. The idea that eventually emerged was chilling in its simplicity: if an aircraft could be turned into a bomb, why bother planting a bomb inside it? Hijack the aircraft. Control the aircraft.
Fly the aircraft into the target. The terrorists’ imagination had moved from destroying an aeroplane to weaponising it. And KSM’s original vision went considerably beyond the four aircraft eventually hijacked on September 11. The intended targets included, but were never limited to multiple American landmarks and institutions. The plan envisaged simultaneous attacks on an extraordinary scale. The point is worth remembering in 2026 because terrorism rarely begins with the operation that eventually reaches the headlines.Terrorists experiment. They test vulnerabilities. They study security. They improvise. They learn from failure. And they try again. The Director General of Nigeria’s Department of State Services (DSS), Tosin Ajayi insists that “is why intelligence matters.” The plots we never heard about There is another side to the 9/11 story that deserves greater attention on its 25th anniversary. The attacks we remember are the attacks that succeeded. But the history of counterterrorism is also a history of attacks that never happened. In Nigeria, for instance, the DSS continues to intercept communications and foil plots that would have been very devastating to the peace of the country.
But the reports that grab the headlines are always about the terrorists who succeed. The greatest success can produce the least visible evidence.
There is no memorial to a passenger who was never killed. There is no photograph of the aircraft that never exploded. There is no anniversary for the family that was never bereaved. That is the strange mathematics of intelligence. The greatest success can produce the least visible evidence. The 2006 liquid-bomb plot in Britain is one of the clearest examples. British intelligence and law-enforcement agencies, working closely with American counterparts, uncovered an al-Qaedalinked conspiracy to destroy several transatlantic passenger aircraft with liquid explosives. The plot was sufficiently advanced to demonstrate the terrifying vulnerability of civil aviation. The arrests in Britain prevented the conspirators from carrying out what could have become one of the worst aviation atrocities since 9/11. And here lies the point that should never be lost in the history. Thousands of people may have lived because intelligence officers connected pieces of information before the terrorists could connect the pieces of their own plan.
That is intelligence at its finest: Not revenge. Not retaliation. Prevention. (Vanguard will provide details of that security intervention next week)
The liquid that changed aviation
The legacy of that plot remains visible every time an airline passenger is forced to think twice about carrying a bottle of liquid through airport security. What passengers sometimes regard as an annoying restriction has its roots in a very real vulnerability exposed by the 2006 conspiracy. The lesson was brutally simple: terrorists had moved beyond conventional explosives and were looking for ways to disguise components of a weapon as ordinary objects. Security consequently had to move ahead of the threat. That principle is as relevant today as it was then. Because the terrorist who can exploit yesterday’s security system is already planning tomorrow’s attack.
The British lesson
The British success was not simply about having clever intelligence officers. It was about a system capable of turning fragments into a picture. It involved surveillance. Human intelligence. Communications intelligence. International cooperation. Police work. Analysis. And, crucially, information-sharing. The Americans had pieces of the puzzle. The British had pieces. The threat crossed the Atlantic. So did the intelligence. This is perhaps the most important lesson for Nigeria.
Nigeria must learn before the next attack
Nigeria has its own long and painful counterterrorism experience. Boko Haram has been followed by ISWAP’s evolution into a sophisticated regional threat. Kidnapping networks, bandit groups, arms traffickers and terrorist organisations increasingly exploit the same porous spaces, criminal economies and communication technologies. The threat is no longer confined neatly to one forest, one state or one national border.
A recent UN assessment noted that ISWAP has expanded its use of drones and exploited commercial channels to acquire components, while terrorist logistics continue to exploit routes running through Libya, Sudan, Chad, Cameroon, Niger and Nigeria. That should worry every intelligence professional. Because the next great terrorist vulnerability may not look like the last one.
The war must move from reaction to anticipation
Nigeria has made progress in this direction. In 2026, the Federal Government said its security response increasingly rests on intelligence gathering, surveillance, community engagement and inter-agency coordination. It has also strengthened its counterterrorism relationship with the United States, including intelligence-sharing and capacity-building. That is encouraging. But the test is whether the intelligence architecture can consistently anticipate rather than merely react.
