Barring some unforeseen development, Mrs Merkel expects to celebrate ten years as Chancellor of Germany in November – and there is no challenger in sight. When she first came to power, Tony Blair, George W Bush and Silvio Berlusconi were in office. She has seen them all off. While there are rumours she may choose to stand down and pursue some other role, possibly as UN secretary-general, or as an EU president, there is no obvious successor in Germany.