Theresa May is right on extremism. We cannot be held back by a fear of causing offence | Matthew d’Ancona

After the London Bridge attack the prime minister’s pledge to tackle radicalisation was essential. Terror will not be contained by half-measuresFrom the tactical froth of a dispiriting election campaign, a monstrous beast raises its head once more. Long after the twists and turns of this particular political contest are forgotten, we shall still be dealing with the poisonous ideology that spawned the horrors of Manchester and, now, of London Bridge and Borough Market. Whichever party wins