From Our Own Correspondent

It's been a momentous week in South Sudan, where a national unity government has been formed under President Salva Kiir as his old enemy, the rebel leader Riek Machar returned to the capital Juba for the first time since the civil war broke out in December 2013. Can these men now lead their country to a much longed-for peace? Imagine being fined four years' salary for having a second child. That's what used to happen in China. We meet a rare family in Beijing with two daughters. Cuba's Fidel Castro is celebrating his 90th birthday this year. Last week he effectively said goodbye to his key supporters, but there is no sign that his fellow revolutionaries, now well into their eighties, are going to retire any time soon. If you'd suffered the kind of radioactive contamination that came with the fallout of the accident at Chernobyl, would you risk building a nuclear power plant? Ukraine's neighbour Belarus is hoping that atomic lightning won't strike twice. And if you're going on a pilgrimage to Lourdes in th