LONDON — A British judge sentenced three men to life in prison on Monday for plotting to bomb at least seven trans-Atlantic airliners with liquid explosives smuggled aboard in soft-drink bottles, concluding the largest counterterrorism investigation in British history, news agencies reported. They were convicted last week after a six-month trial.
While the men received life sentences, they will be eligible for parole after a prescribed minimum term. The man described by the authorities as the plot’s ringleader, Abdulla Ahmed Ali, was given a minimum of 40 years in prison. Another conspirator, Assad Sarwar, was jailed for at least 36 years, while Tanvir Hussain, described as the man responsible for acquiring and assembling the explosive devices at a London warehouse, received a minimum term of 32 years, the Press Association reported.
The discovery of the plot three years ago threw the global airline industry into chaos. The bombers’ plan to drain plastic soft-drink bottles with syringes and refill them with concentrated hydrogen peroxide, a bleaching agent also used as a propellant for rockets, led to new measures prohibiting passengers from carrying all but small quantities of liquids and creams onto flights.
With those measures still in force and causing backups at airport security checkpoints, the police and intelligence agencies in Britain and the United States had waited anxiously for verdicts in the six-month trial at Woolwich Crown Court in London, where eight men were accused of conspiracy to stage the airliner bombings.
The judge who delivered the sentencing, Justice Richard Henriques, said Monday that had the conspiracy been successful it would “stand alongside the events of September 11, 2001 in history.”
Prosecutors said the plot, which would have been carried out on a single day, could have killed at least 1,500 people, which by that measure would have made it second only to the Sept. 11 attacks as the most serious terrorist plot in modern history.
Last year, a trial failed to reach verdicts on the airliner-bombing charges against the defendants then being tried, though they were convicted of lesser charges. So the stakes were especially high in the second trial for the main agencies involved in uncovering the London plot, including Scotland Yard and Britain’s secret intelligence agencies, MI5 and MI6, as well as the C.I.A., the National Security Agency and the F.B.I., among American agencies involved.
Documents and computer files found at the plotters’ homes after their arrests in August 2006, showed that they had earmarked airline schedules for seven flights leaving London for New York, Washington, Chicago, San Francisco, Montreal and Toronto, with aircraft operated by American Airlines, United Airlines and Air Canada. Evidence at the trial showed that the plot aimed to detonate the bombs nearly simultaneously, with the aircraft over the Atlantic Ocean.
The plotters’ intent, intelligence officials said, was to show that security measures adopted after Sept. 11 were insufficient to foil the kind of low-technology, “asymmetric” attacks favored by Islamic extremists in their war with the West. Evidence at the London trial showed that several of the plotters, like those of Sept. 11, had traveled to Pakistan and Afghanistan for indoctrination and training by extremist groups linked to Al Qaeda.
A total of eight men were in the dock during the trial. Four of the eight — Ibrahim Savant, 28; Arafat Waheed Khan, 28; Waheed Zaman, 25; and Donald Stewart-Whyte, 23 — were found not guilty of plotting to bomb the airliners. The eighth man, Umar Islam, 31, was found guilty of an alternative charge of conspiracy to commit murder, as were Mr. Ali, Mr. Hussain and Mr. Sarwar at the first trial, which ended in September 2008.
Keir Starmer, the director of public prosecutions, said after last week’s verdicts that he would seek a third trial — highly unusual in Britain — for the three men found not guilty of plotting to bomb the airliners but left in limbo by the jury’s failure to reach verdicts on the charge of conspiracy to commit murder.
Mr. Starmer said “there remains a realistic prospect of a conviction against each defendant” — Mr. Savant, Mr. Khan and Mr. Zaman. A hearing will be held on Oct. 5 to consider whether to proceed to another trial. “I have concluded, in this exceptional case, it is in the public interest to seek a further trial,” Mr. Starmer said.
Scotland Yard officials estimated the total cost of the case at more than $60 million, another factor that weighed heavily as the verdicts came in. Over the weekend, there had been fears the trial would end, like the first, with a hung jury on the main charges of plotting to bomb airliners. As the jury reached the end of a second week of deliberations, the judge called the jurors into court on Friday and told them he would accept 10-to-2 majority verdicts — allowable under British law — if they were unable to reach unanimous decisions.
Behind the scenes, the case caused major strains between American and British intelligence agencies and investigators. The Americans were deeply involved from the start because of the role that American electronic intercepts played in uncovering the plot, and because the principal targets were American planes and passengers.
But officials familiar with the case said there were bitter disputes over the arrests in 2006, with the Americans saying they believed that the British, who staked out the conspirators for months, waited too long to round them up, raising the risk of an attack. The British, by contrast, were angered by the American pressure, which they said forced them to make the arrests before they had all the evidence necessary to ensure convictions.
A major stumbling block at both trials was that British court procedures do not allow the use of intercepted telephone conversations and other electronic intercepts. Television documentaries shown in Britain have included secret police videotapes showing some of the plotters engaged in what appeared to be preparatory work on the bombs at the suburban London bomb factory and discussing the destructive potential of the bombs.
Mr. Ali and several other defendants testified at the trial that they had never intended to bomb airliners, but planned what they called “a political stunt,” involving setting off minor explosions in garbage bins outside airline offices in Terminal Three of Heathrow airport, the London base for the three airlines they earmarked in the flight schedules. Their purpose, they said, was to frighten people, not to kill them.
But experiments by British explosives experts cited in court found that the bombs the plotters planned to use could blow aircraft apart at 30,000 feet.
Prosecutors showed the court extensive evidence showing how the men bought material for the bombs, and how some of it, including the hydrogen peroxide, was hidden in woods outside a town northwest of London. The jury was also shown so-called martyrdom videos prepared by two of the plotters, Mr. Ali and Mr. Hussain.
A common theme in the videos was exacting revenge on Britain and the United States for their interference in Muslim countries, especially the wars in Afghanistan and Iraq.
“We have warned you enough,” Mr. Ali said. “We have warned you again and again to leave our lands.” In his video, Mr. Hussain said his only regret was that “I can’t come back and do this again and again until people come to their senses and realize, ‘Don’t mess with the Muslims.’ ”
