In many parts of the world, charities are trying to deliver much-needed aid to desperate people living in areas controlled by militant groups. What do they do when counter-terrorism laws ban them from contact with those de facto authorities? Risk of prosecution has now created a climate of fear in many aid agencies - and the UN wants counter-terrorism policies redrawn to ensure lives can be saved without charity workers risking jail. Tim Whewell reports from Gaza - and talks to aid workers operating in Syria, Somalia and other places - on the practical and moral dilemmas involved. Producer: Paul Grant.