British Prime Minister Keir Starmer vowed on Thursday to deal with “the root causes of extremism and antisemitism” after the stabbing of two Jewish men in the heavily Jewish London neighborhood of Golders Green.

Starmer said in a video statement that the fight against antisemitism is an issue for “everyone in this country,” and vowed to stand with the Jewish community after the attack, which authorities have formally declared a terrorist incident.

But as he visited Golders Green on Thursday, protesters gathered to criticize what they said was longstanding government inaction.…