Despite Pope Francis’s desire for a simple and comparatively low-key send-off, those tasked with organising and delivering the funeral of the 266th bishop of Rome still face a vast array of logistical, technological and security challenges. With as many as 170 foreign delegations – including those of Donald Trump, Volodymyr Zelenskyy and Prince William – expected to descend on the Vatican for Saturday’s funeral, along with crowds of up to 200,000 people, those overseeing the event are in for a hyper-vigilant few days. The security operation will be further complicated by the fact that the Liberation Day public holiday, which...