WASHINGTON • The United States-British missile strike believed to have killed "Jihadi John" came together at lightning speed, but was months in preparation.
Shortly before midnight last Thursday, two US MQ-9 Reaper drones and one British MQ-9 cruised above Raqqa, the Syrian heart of the self-declared caliphate of the Islamic State in Iraq and Syria (ISIS) that stretches deep into Iraq, US officials said.
The aircraft's controllers monitored two people who had entered a car. One, they were convinced, was Mohammed Emwazi, the British computer programming graduate who catapulted to infamy in August last year when he presented the beheading of US journalist James Foley, the first of several grisly videos in which he presided over the decapitations of foreign hostages.
Brandishing a knife, dressed head to toe in black, and speaking with a London accent, Emwazi became known as "Jihadi John", the most potent symbol of the group's brutality and a high-value target for US and British intelligence agencies.
US officials said the US and British operation to kill Emwazi had been in the works well before the drones unleashed Hellfire missiles on Thursday.
US and British agencies had tracked the ISIS propagandist and alleged executioner for months before delivering information on his movements and location to the US military, officials said. In the days leading up to the strike, Emwazi had been moving around Raqqa, visiting his wife's residence and an ISIS media operations cell, said one US official, speaking on condition of anonymity.
The subsequent US and British operation unfolded quickly. Two missiles destroyed the car targeted in the strike. The US expressed growing optimism on Friday that Emwazi was dead but cautioned that a formal determination would take time.
"We're 100 per cent sure the guy we hit is dead. We are reasonably sure the dead guy is Jihadi John," said one US official, speaking on condition of anonymity.
The strike illustrates an apparent improvement in Western intelligence-gathering over the past year or more in a rugged region where reliable on-the- ground information is scarce and where the US has struggled to infiltrate the extremist group.
Emwazi was mainly tracked and targeted through surveillance technology that included both satellite and ground-based sensors rather than informants on the ground, said one US government source familiar with details of Thursday's operation.
Britain's GCHQ intelligence agency and the US' National Security Agency have extensive electronic surveillance coverage of the region, officials say.
The attack on Emwazi follows a series of strikes by the US and Britain against other British recruits to the ISIS movement.
In August, a Birmingham man regarded as one of ISIS' top computer experts, Junaid Hussain, was killed in a US drone strike. Around the same time, two British recruits to ISIS, Reyyad Khan and Ruhul Amin, were killed by British drone strikes, said a European government source.