If, on the other hand, the attacks were the work of al-Qaeda, they would show that Islamist terrorists have built up a sophisticated and effective infrastructure within Europe that might be used to equally deadly effect elsewhere.
He also deploys colloquialism to deadly effect.
Campaigners said African Americans were treated unfairly to deadly effect.
Instead al-Qaeda had infiltrated them, with deadly effect.
But Sunday was the first time that bombs had been used to such deadly effect on worshippers.
These missiles have been used with deadly effect against airliners by separatist groups in former Soviet republics.
Pressure cooker bombs were the devices used to deadly effect in the bombing of the Boston Marathon in 2013.
Hassan Ngeze owned a newspaper, Kangura, that, with deadly effect, urged its Hutu readers to murder Tutsis.
Barça, at times overindulgent, at other times patient, and then quickening the thrusts with deadly effect, tormented the Brazilians.
This deadly effect occurred only if the flies consumed alcohol after the wasps laid eggs in them.
But, he said, he had seen firsthand the deadly effect of obesity on patients he has treated in the city.
