After all, they argue, they are only just getting into their stride. Their first two terms were spent in originating brilliant policies calculated to flower and flourish under their continued leadership, but bound to fail or be ruined under the rule of their hapless successors. Unless, that is, they can find a way of still running the country in some other guise.

Russia’s Vladimir Putin and South Africa’s Thabo Mbeki have been giving the matter much thought. President Putin discovered that there was nothing to stop him becoming his country’s prime minister in future. What was then needed was that the new Russian president would not be a strong figure with ideas of his own. But how to achieve this? Putin had an idea: why don’t I pick my successor myself? And so it shall be.

Mbeki will have a much harder time of it. His wheeze, when he ends his stint as South Africa’s president in 2009, is to be the president of the ruling party, the African National Congress, and, following Putin’s example, exercise power through a malleable new national president, preferably one of his own choosing (he hoped his successor would be a woman, he has said).

Alas, he had not reckoned with the popularity of Jacob Zuma, in spite of his involvement with a dodgy fraudster and a rape trial that resulted in his acquittal, but left him with a sullied reputation — or so it seemed. But two weeks ago, the influential Congress of South African Trade Unions became the latest body to plump for Zuma as the next head of the ANC (the election is in December) and argue that the ANC president should also become the president of South Africa in 2009, which would rule Mbeki out. His dream, unlike Putin’s, is nearing its end.

In Argentina, they do things differently, and with more panache. Later this month, Nestor Kirchner ceases to be president of Argentina — to be succeeded, almost certainly, by his wife Cristina. He didn’t have to go. He could have served another term, but decided instead to designate his wife, herself a senator, to fight the elections on October 28. She is an experienced and respected politician in her own right, but no one doubts the influence her ex- president husband will exercise. (At least he’ll be alive. Juan Perón, it can be argued, ruled Argentina from his grave, through his third wife Isabella, who took over the presidency when he died without bothering to get a public mandate.)

It may even be possible for a former US president, his two terms completed, to regain power — and I’m not just talking about Bill Clinton’s private influence over Hillary. It may be constitutionally valid — expert legal opinion is divided — for an ex-president to become a vice-president. In theory, Clinton or George Bush could re-emerge as a shadowy Cheney-type figure running the country. How grateful we should be that our head of state is a monarch with no time limit.

Guardian