It's a pattern that, sadly, is becoming too familiar in Europe. The initial shock of the latest terrorist attack soon gives way to anger, sadness, prayers, and a gnawing sense of powerlessness. And then, eventually, we move on — until the next time.

Yesterday's attack in London had the particularity of actually occurring on the one-year anniversary of the Brussels metro and airport attacks that killed 32 and wounded more than 300 people. It is, perhaps, the cruel irony of current events: Brexit or no Brexit, EU or Westminster, Islamic terrorism was striking again at the heart of another European capital.

The British-born attacker, whose complete identity hasn't been revealed yet, mowed down pedestrians with a car, killing two people and wounding about 40. Then, after crashing into the gate in front of Parliament, the assailant fatally stabbed a policeman before being shot dead. Though first indications seemed to indicate the assailant was acting alone, police raids this morning have led to the arrest of eight people in London and Birmingham.

High security in Brussels — Photo: Frankieleon

In a statement this morning, British Prime Minister Theresa May said the attacker had been "investigated by MI5 in relation to concerns about violent extremism" some years ago but she described him as a "peripheral figure" that was "not part of the current intelligence picture." Soon afternoon UK time, several news agencies reported that ISIS was claiming responsibility for the attack.

Despite the lower death toll, the modus operandi in Westminster recalls the July attack in the French city of Nice and the Berlin Christmas market attack. As the dismantlement of yet another jihadist cell this morning in Italy shows, intelligence services across Europe have tightened the noose around the kind of organized networks that struck last year in Brussels. But so-called lone wolves resorting to "low-cost" or "low-tech" terrorism are more difficult to see and stop. Hard lessons for all of Europe, and beyond.