Alexander Litvinenko’s final testament, released after his death on Thursday evening, is deeply moving. It is also political dynamite. He thanked the hospital that battled to save him. He thanked his friends and the British authorities and paid tribute to the country that had granted him citizenship a month before his death. And dramatically accusing President Putin of having no respect for life, liberty or any civilised value, he said the Russian leader may have succeeded in silencing one man, “but a howl of protest from around the world will reverberate in your ears for the rest of your life”.His...