Khalid Masood, the 52-year-old British man who killed four people in a rampage last week in London, was not associated with al-Qaida, ISIS or any other Islamic terrorist group, British authorities say.
But, they added, it is possible Masood was influenced by Muslim extremism. Whether that was a factor is still being investigated.
Dismissing a direct link with terrorist groups misses the point, however. It is that in many countries, including ours, murderous attacks have been launched by people in sympathy with the terrorists.
So-called lone wolf terrorists did not exist before groups such as ISIS and al-Qaida began their global propaganda campaigns. Wiping out the source of the extremism is imperative.