Next month Chinese President Hu Jintao and most of the Communist Party leadership will begin to hand over power to younger colleagues in a once-a-decade political transition. Over coming months, scores of leaders across the party, the government and the military will be replaced in a painstakingly choreographed and at times divisive change-over at the top of the world's second-largest economy, which is growing in diplomatic and military strength.

Why does the change matter for the world?

China's politics are secretive, so policy-making seems like a black box. It doesn't help that Chinese leaders, unlike Western politicians, tend to be reserved in public, giving them a bland sameness. Still, China has been a global success story, with its rapid growth lifting hundreds of millions out of poverty and buoying the world economy. But its juggernaut economy of the past two decades is flagging just as a new middle class and tens of millions of rural migrants expect a better life.