Politics can be a cruel business. No one knows that better than Britain's former foreign secretary David Miliband. He was hot favourite to lead the UK's Labour party after its dismal 2010 election defeat, but he lost out to his younger brother Ed. His steady rise to the political summit was halted, but he remains a Labour MP, and he still makes carefully timed interventions in foreign policy and national politics. Without the trappings of power, how does David Miliband maximise his influence?