Last week’s terrorist attack in London took two innocent lives. But British counterterrorism services will have breathed a sigh of relief that this latest attack again involved knives, and not firearms or explosives.

Don’t misunderstand me: Any successful terrorist attack is a cause for great lament. While the attacker was able to replicate the 2017 London Bridge terrorist attack, he inflicted fewer casualties and less terror on the British capital. Still, counterterrorism police and intelligence officers take their work personally, rightly viewing themselves as the shields for life against death. They will be saddened and frustrated by what has occurred.