Moral logic that seems crystal clear on paper often becomes murkier on contact with reality. So it is with the question of how to pick a path through the right to protest against Israel’s actions in Gaza, and the rise in antisemitism that has been seen across Europe since Hamas committed the terrorist atrocities of 7 October 2023. Last week, the focus was on university campuses, as Rishi Sunak convened a roundtable of vice-chancellors at Number 10. In theory, the guardrail is straightforward: people’s democratic rights to protest must be protected, but any spillover into antisemitism is to be loudly...