LONDON—Britain’s security services responded to criticism over their failure to prevent the bombing of an Ariana Grande show in Manchester this year by revealing that they recently stopped a terrorist attack on Prime Minister Theresa May.
On the same day that an independent report found 22 lives could have been saved at the May 22 concert “had the cards fallen differently,” the head of MI5 briefed politicians that the counterterror services had thwarted nine terror plots in nine months.
Britain’s security services are traditionally far more reticent to speak out than their U.S. counterparts, but MI5 boss Andrew Parker felt the need to defend his officials this week in a briefing to Cabinet ministers.
He outlined some of the security services’ recent successes, which included the arrest of a man who was allegedly plotting a devastating attack on the heart of the British government.
MI5 said the plot was to detonate an improvised explosive device at the famous gates of Downing Street and then use the ensuing chaos to rush inside and assassinate Theresa May in a second wave of the attack, using knives and a suicide vest.
Naa'imur Zakariyah Rahman, 20, appeared at Westminster Magistrates Court on Wednesday, charged with preparing acts of terrorism. The Bangladeshi-British citizen was arrested by Scotland Yard’s Counter Terrorism Command on Nov. 28 along with Mohammed Aqib Imran, 21, who has been charged with trying to join the Islamic State terror group.
Britain suffered four terrorist atrocities in just three months earlier this year, the most sustained period of terror-related violence in a generation.
The surge in violence prompted the government to commission an independent analysis of the security services’ work during that period.
David Anderson, a senior lawyer, reported that authorities had been on the trail of some of the extremists involved in all three of the Islamist terror attacks. It was only the attack on Muslims leaving a mosque in North London that had totally “blindsided” them.
“Khalid Masood (Westminster) and Salman Abedi (Manchester) had both been subjects of interest, and Khuram Butt (London Bridge) remained under active investigation,” he wrote. “MI5 and counterterrorism policing got a great deal right; particularly in the case of Manchester, they could have succeeded had the cards fallen differently."
Anderson said he rejected MI5’s own conclusion that it would not have been possible to thwart Abedi’s plot to attack the Grande concert. A meeting to discuss Abedi had been scheduled by the authorities after a number of intelligence leads, but that meeting was never held because his devastating attack had already taken place.
“It is unknowable whether such an investigation would have allowed Abedi’s plans to be pre-empted and thwarted,” Anderson said. “In retrospect, the intelligence can be seen to have been highly relevant to the planned attack.”
In October, Parker gave a rare public address in which he admitted that further terror attacks were inevitable in Britain, which was experiencing more terrorist activity than at any time in his three-decade career in the security services.
His warning had not succeeded in securing an increased budget, but Home Secretary Amber Rudd said Tuesday that she may reconsider that as the security services struggle to keep tabs on around 3,000 people of interest with hundreds of trained fighters returning from the ISIS frontlines in Iraq and Syria.