In November 2008, Pakistani terrorists targeted Mumbai in the most horrible and audacious terror attack since 9/11. Five years on, the men who masterminded the attack are still free in Pakistan and plotting more attacks. India and America are at risk from them. The basic details of the attack are well known. Ten terrorists of Pakistan-based Lashkar-e-Toiba attacked two fabulous hotels, The Oberoi and the Taj, the city’s train station, hospital, a restaurant that catered to foreign visitors and the rich, and a Chabad House for visiting Israeli and American Jews, and killed 166 people and injured over 300 between November 26 and 29. Among the victims were five American citizens. In India, the horror is known as 26/11 and the battle to kill the attackers as Operation Black Tornado. For the terrorists and LeT, it was Operation Bombay. The Mumbai attackers’ tactics have since been copied by others, most recently by militants who attacked the Westgate shopping mall in Nairobi, Kenya.

Today, we know a great deal more about the attack than ever, its planners and the critical American hand in the plot. LeT had carefully chosen the targets and meticulously researched them over several years with considerable assistance from Pakistan’s intelligence service, the Directorate for Inter-Services Intelligence or ISI, and al Qaeda. They had different agendas for the operation but their targets were the same-Indians, Americans and Jews, the targets of the global jihad started by al Qaeda in the late 1990s. I had pointed this out to President-elect Barack Obama and his transition team during several briefings in my role as South Asia transition director after his election. The attack was intended to dramatically change the future of South Asia, perhaps even by provoking a war between the two nuclear-armed neighbours. India, however, did not fall into the trap.

The most fascinating aspect of the meticulous planning was the role of David Coleman Headley, an American of Pakistani descent, in intelligence collection that preceded the attack. He admitted his role in the attack and pleaded guilty to conspiracy to commit murder in March 2010. Headley was born Daood Sayed Gilani in Washington DC in 1960. His Pakistani father worked for the Voice of America. Headley got into trouble with the law as a youth and was arrested on drug charges. He became an asset of the United States Drug Enforcement Administration and was sent to spy on Pakistani drug dealers. There, according to his guilty plea, he joined LeT during one of his visits in 2002. Over the next three years, Headley travelled to that country five times for training in weapons handling, intelligence collection, surveillance, clandestine operations and other terrorist skills. He was trained by both LeT and ISI. He also developed contacts with al Qaeda.

In 2005, he was given the task of travelling to India from the United States to conduct surveillance for the Mumbai attack. As a first step, LeT told him to change his name to David Coleman Headley to hide his Pakistani identity when travelling abroad. He made five trips to India between 2005 and 2008, each time stopping in Pakistan on his way back to the US to get new instructions from let leaders and isi officials and to report his surveillance results. He visited each of the targets, recorded their locations with GPS handsets, carefully studied security around each and, thus, became one of the masterminds of the plot.

In his confession and during interrogation by Indian security officials, Headley said ISI was actively involved at every stage of the planning of the raid. At each of his meetings in Pakistan, he met with ISI officers as well as let leaders. Sometimes, ISI gave him assignments separate from LeT such as tasking him to take pictures of a nuclear facility near Mumbai. The intelligence agency also gave him money, including an initial $25,000 in cash, to help set up his cover story in India, and provided training, including by elite Pakistani naval commandos, to the attackers. ISI, according to Headley, was especially pleased with the choice of the Jewish Chabad House as a target. A new book, The Siege: 68 Hours inside the Taj Hotel, by Cathy Scott-Clark and Adrian Levy adds a new wrinkle to the narrative. Their investigations in Pakistan, India and the United States led them to believe that LeT and ISI suspected Headley was a double agent, still secretly giving information to the Americans. So, as the date for the attack drew close, Headley was frozen out of the plot so he could not reveal any details. The plotters were also worried about his three wives, one of whom had reported his suspicious activity to the American Embassy in Islamabad. let leader Hafiz Saeed had to at one point intervene personally in Headley’s complicated love life to keep the plot a secret. Headley was adept at double games, and we almost certainly still don’t know all of them.

After the strike on Mumbai, Headley worked with al Qaeda on an even more ambitious plan to attack Copenhagen in 2009, probably during the Global Climate Change Summit that year. A tip-off from British intelligence, however, led to his arrest and subsequent conviction. Headley’s al Qaeda contact was the notorious Pakistani terrorist Ilyas Kashmiri who was also trained by ISI. Kashmiri was so effective in his job that Osama bin Laden tasked him in 2010 to try to assassinate President Obama. Fortunately, the American drones got to him first.

However, the mastermind of the Mumbai attack plot, let leader Hafiz Saeed, remains free in Pakistan. He continues to be a darling of ISI and regularly calls for more attacks on India and the United States. There is an American bounty for information that could lead to his arrest but it seems unlikely he will be brought to justice any time soon. His LeT apparatus, meanwhile, is still training legions of terrorists like those sent to Mumbai and operates closely with the Pakistani deep state. isi officers involved in the plot are also free. The previous government of President Asif Zardari was never strong enough to try to tackle ISI, and Prime Minister Nawaz Sharif has plenty on his plate already so he too won’t go after the masterminds of the attack.

Some people have suggested ISI’s involvement in the attack was probably only at a low level and that the top army commanders did not know about the plot. As a former professional intelligence officer, I find that argument ridiculous. Running an American citizen like Headley for years was a major ISI operation that would have been overseen and monitored, if not micro-managed, by the top brass of the service. They knew what the plan was and they approved it.

Five years after Mumbai was scarred, justice is yet to be served. The small fish, Headley and Kasab, have been brought to account for their role but the big fish are still free, and dangerous.