The trial, which ended Monday, highlights key differences between US, British counterterrorism approaches.
It was supposedly the biggest terrorist plot since 9/11, a grotesque plan to blow up seven transatlantic planes simultaneously that would have killed more than 1,000 people had it not been foiled two years ago.
But an inconclusive verdict in the British trial of seven alleged perpetrators has raised fresh questions about the plot, the police operation that unraveled it, and the international counterterrorism collaboration so vital to defeating extremists.
After a five-month trial, the jury decided Monday that three of the seven accused – Abdulla Ahmed Ali, Assad Sarwar, and Tanvir Hussain – had indeed been plotting to kill using a form of hydrogen peroxide liquid bomb disguised as a soft drink. But the jury could not decide whether aircraft were the target. They also decided that four other defendants were not guilty. Prosecutors are considering a retrial.
Terrorism experts say the verdict was a setback to British counterterrorism efforts, which have notched up a volley of successes over the past three years.
Operation Overt, as it was known, was the biggest counterterrorism investigation in British history, costing around $60 million since the day in May 2006 when Britain's MI5 intelligence agency began focusing on Mr. Ali. The day of the arrests three months later brought mayhem to international aviation; security measures introduced involving a ban on soft drinks in hand luggage persist to this day.