Succession planning is tricky in business. It is even worse in politics. Just consider the countries that are currently making a mess of efforts to find a new leader.

In Russia, Vladimir Putin has promised to obey the constitution and not seek a third term as president. But he and his supporters are wrestling indecorously with the problem of how to find a suitably pliant successor. In South Africa, enormous political tensions are being generated by Jacob Zuma’s efforts to displace President Thabo Mbeki as the head of the ruling African National Congress. British politics was dominated for years by Gordon Brown’s efforts to dispatch the then prime minister, Tony Blair.