Today marks 25 years since the terrorist attack in the US, BBC analysis: Spies, strategies and missed opportunities!

The first duty of a government, as countless leaders have said over the decades, is to protect its population. On September 11, 2001, the US manifestly failed to do so. The information was there, yet tragically, no one connected the dots in time.

September 11, as the attacks on the US became known, defined, along with the response, a generation of foreign, security and intelligence policy for the first two decades of this century.

On September 11, 2001, as al-Qaeda’s suicide pilots steered those hijacked planes toward the World Trade Center, I was just finishing an assignment at our Middle East bureau.

As a Palestinian taxi driver took me through the pine-covered hills west of Jerusalem toward Tel Aviv’s Ben Gurion Airport, he suddenly turned up the car radio. “Something big has happened in America,” he said. He was not exaggerating. A total of 2,977 victims died that day.

The attacks did not come out of nowhere. The CIA had known about the al-Qaeda network and its exiled Saudi leader, Osama Bin Laden, for years before 2001. It even had a dedicated task force tracking him.

Nine days after the September 11 attacks, then-US President George W. Bush declared the “War on Terror.”

In the 25 years that followed, there have been many intelligence successes, as well as failures, on both sides of the Atlantic. The successes include plots that were thwarted and suspects who were arrested, brought to trial, convicted and imprisoned.

But what can we say about the bigger picture? How have intelligence gathering, counterterrorism and strategic planning changed in the 25 years since the worst terrorist attack in US history?

A colossal intelligence failure

No one can dispute that September 11 was a colossal intelligence failure, or, more specifically, a failure of imagination within the US intelligence community. At the time, both the CIA and the FBI possessed information that, had it been shared properly, might have prevented what happened.

The subsequent 9/11 Commission Report blamed the US government for “failures of imagination, policy, capabilities and management.” The report concluded that the CIA and FBI had failed to assess intelligence properly, share information with each other and take sufficient steps to disrupt the plot.

That most fundamental lesson has since been largely, though not completely, learned, and information sharing among Western intelligence agencies is infinitely better than it was in 2001. Old rivalries between, for example, MI5 and Counter Terrorism Policing have been broken down, first through “regional fusion centres” spread across the UK and now, most recently, with the creation of the high-security Counter Terrorism Operations Centre in London.

Here, MI5 intelligence officers can literally be found sitting alongside police officers whose job is to take executive action to stop a terrorist plot.

They may likewise be sitting beside a US federal agent from the FBI or a language specialist seconded from GCHQ.

Since September 11, US intelligence has also undergone a radical reorganisation, with the creation of a National Counterterrorism Center just outside Washington, DC, and the Office of the Director of National Intelligence, to ensure that information is shared where necessary among the 18 separate US intelligence agencies.

The relationship between the CIA and its UK counterpart, the Secret Intelligence Service, better known as MI6, is perhaps the closest in the world. This is complemented by the Five Eyes alliance, which brings together intelligence from the US, the UK, Canada, Australia and New Zealand.

Nevertheless, catastrophic failures of intelligence, assessment and strategic planning have occurred since the planes struck the Twin Towers. In the run-up to the US-led invasion of Iraq in 2003, MI6 carelessly allowed its intelligence to become politicised, resulting in the greatest loss of reputation the organisation had suffered since the betrayals by double agent Kim Philby and other Soviet spies in the 1950s and 1960s.

Against a backdrop of intense political pressure from Washington to produce evidence that Iraq, under President Saddam Hussein, still possessed “Weapons of Mass Destruction” (WMD), MI6 supplied Prime Minister Tony Blair’s government with what turned out to be flawed intelligence. Iraq had indeed possessed WMD in the past, but they were all destroyed after the 1991 Gulf War.

Following the 2003 invasion of Iraq, MI6 completely overhauled the way it assesses raw intelligence, known as CX, received from agents in the field. Today, there is a clear separation between agents, whose job is to gather that intelligence from sources in countries such as Iran or North Korea, or from inside banned terrorist groups such as al-Qaeda, and the reporting team, whose job is to scrutinise and challenge that intelligence, often sending it back with requests for more evidence.

“The [2003] Iraq War was based on deeply flawed intelligence,” says General Sir Richard Shirreff, who served in Iraq as a divisional commander. “Have we learned from it? No, I think we are poor at learning… As a commander, it was so clear that we were heading for strategic failure.”

Another inquiry followed the invasion of Iraq, culminating in the Butler Review. It concluded that UK intelligence on Iraq’s alleged weapons of mass destruction programme “was seriously flawed and relied too heavily on unverified sources.”

The Security Service, MI5, has also had its own failures, amid many undeniable successes in preventing terrorist plots. “After September 11,” says Lord Jonathan Evans, who led MI5 from 2007 to 2013, “the assessment was that the most immediate security threat to the UK was the terrorist threat from al-Qaeda and individuals and groups associated with it.”

But with a database at the time containing more than 20,000 “Subjects of Interest” and a large number of investigations running simultaneously, MI5 faced, and still faces, a daily challenge that requires prioritisation. It has not always got it right.

In 2005, the Security Service failed to prevent the suicide bombings in London on September 7, which killed 52 people. The Security Service was aware of Mohammed Sidique Khan, the man who turned out to be the leader of the group, but did not know what he was going to do. The 2017 Manchester Arena bombing was another, more recent failure.

Today, the threat from terrorism has not disappeared, but, Lord Evans says, “the picture has changed. Non-state terrorism remains a serious concern, but state threats… have become increasingly serious and are at least as significant a national security concern as non-state terrorism. These threats come, in different forms, from Russia, Iran, their proxies and China.”

It could also be argued that US President Donald Trump’s decision to join Israel in attacking Iran this year was a failure of intelligence imagination. All of America’s allies in the Persian Gulf knew there was a serious risk that Iran would retaliate by closing the Strait of Hormuz.

The warnings were all there, yet Trump appeared to lack a counterstrategy when Iran did exactly what it had threatened to do, causing major disruption to global energy markets.

Moral reckonings

Immediately after the September 11 attacks, there was widespread fear that a second wave was coming. Indeed, al-Qaeda itself promised “a flock of planes” that would attack more buildings. In the rush to prevent such an attack, the US and its allies committed numerous human rights abuses. Suspects were captured in Afghanistan or Pakistan, often on the basis of a weak tip-off. Hundreds were flown, shackled, blindfolded and hooded, halfway around the world to a makeshift prison at the US naval base in Guantanamo Bay, Cuba, where they were imprisoned without trial.

Human rights groups denounced this as a stain on America’s moral conscience.

Scandals involving the abuse of prisoners in US custody in Iraq and Afghanistan have come to light, and some of the individuals involved have been held accountable, but critics say more senior figures escaped consequences. Nevertheless, the US still practises detention without trial at Guantanamo Bay, and did so when it deported more than 200 men from the US to El Salvador’s Terrorism Confinement Center in 2025.

The period immediately following September 11 also saw serious human rights abuses in Britain. In 2004, MI6 was complicit in the abduction and rendition of a Libyan Islamist, Abdelhakim Belhaj, and his wife from Thailand to Libya.

There, he spent years in prison and was tortured by Colonel Muammar Gaddafi’s regime. The case eventually came to light and resulted in a full public apology to Parliament by the Attorney General in 2018. Today, in-house lawyers are reportedly the fastest-growing department within the agencies.

The rise of Russia and China

“We spent the first 20 years of this century focused almost entirely on counterterrorism and counterinsurgency,” said Sir Alex Younger, who was Chief of the Secret Intelligence Service from 2014 to 2020. The late MI6 chief was speaking to me at a literary festival shortly after leaving the top job, adding: “We missed China’s rise as a military power and as a strategic challenge.”

Similarly, General Shirreff wrote the political thriller “War with Russia” in 2016, in which he predicted Russia’s full-scale invasion of Ukraine.

After the September 11 attacks and the “War on Terror” that followed, while Western countries were busy fighting the Taliban and ISIS or trying to deal with the chaotic occupation of Iraq, Russia and China embarked on colossal rearmament programmes, including innovations in hypersonic missiles, for example, that have seriously eroded the military advantage NATO once enjoyed.

“The West’s mistake was not simply that it became distracted by counterterrorism after September 11,” agrees Sam Olsen, Chief Analyst at the security intelligence firm Sibylline. “It also misunderstood the nature of China’s rise, assuming that economic integration would lead to political convergence.”

China, like Iran, Russia and North Korea, is considered a “hard target” for intelligence gathering. In 2001, biometric data was still in its relatively early stages, but the subsequent use of facial, iris and gait recognition has contributed to the considerable modern-day challenge of keeping agents and their handlers from being detected across borders.

So how well, or poorly, does Western intelligence understand China?

Along with Russia, China is now a primary intelligence target for MI6. “Western intelligence understands a great deal about China,” says Sibylline’s Sam Olsen. “The greater risk is that it sees the individual pieces without always understanding what they add up to. Chinese power is no longer only about ships, missiles and troops. It increasingly lies in semiconductors, critical minerals, batteries, ports, telecommunications and industrial capacity… So the problem is often less a failure of intelligence gathering than a failure of strategic interpretation.”

Twenty-five years ago, on the day of the September 11 attacks, US intelligence officers had pieces of the puzzle, an analogy spies like to invoke, but collectively, they failed to put everything together and see clearly what was happening. There is no point in having excellent intelligence gathering if it cannot be used to secure strategic gains.

A world changed beyond recognition

It is clear that the world of intelligence and counterterrorism has changed almost beyond recognition in the quarter-century since that clear, cloudless September morning in New York. With the advent of artificial intelligence and quantum computing, it will continue to change, and in some areas, at an exponential rate.

Nevertheless, in a world full of competing narratives and interests, Western nations do not have a monopoly on intelligence failures, oversights or strategic miscalculations. Other significant examples include Russia’s catastrophic full-scale invasion of Ukraine in 2022 and what some have described as Israel’s “September 11,” the Hamas-led raid from Gaza on October 7, 2023.

Ultimately, it is precisely over major strategic and national decisions that questions remain. Was Britain right to join President Bush’s invasion of Iraq? Was it right to join the US-led Operation Enduring Freedom in Afghanistan, only to abandon the country to the Taliban in a rush for the exit two decades later? These and many other questions continue to reverberate./BBC