UMARU YAR'ADUA

The death last week after a long illness of Nigeria's President Umaru Yar'Adua leaves the country in a state of flux. Not because of his absence; Mr Yar'Adua had been seriously ill, even before he assumed office in 2007, and has not been at the helm since leaving Nigeria last year for medical treatment abroad. But because it dishes the "buggins' turn" system of presidents.

Nigeria is roughly evenly divided between a Muslim north and a Christian south. Tensions between the communities can, and have, run high, as the recent unrest in the central state of Jos has shown. The tacit agreement within the ruling People's Democratic Party is that Muslim and Christian presidents alternate after every two four-year terms. After the Christian President Obasanjo had served two terms, the Muslim Mr Yar'Adua was halfway through his first term. That cosy arrangement has now been abruptly brought to an end, since his deputy Goodluck Jonathan is a southern Christian. Mr Jonathan had already become acting President in February, and has now been sworn in as President. He will undoubtedly pick a Muslim northerner as his deputy, who would have aspirations to become the PDP's candidate in next year's election. But what if Mr Jonathan decides to run himself?

Nigeria matters. It is Africa's most populous country, and a regional and continental heavyweight. It also has huge oil reserves, important for the West. But it has also been spectacularly misgoverned for virtually all of its post-Independence life; even within Africa, it is a byword for corruption. Buggins' turn is not a particularly grown-up way of dealing with the country's many problems; it would be much better, should Mr Jonathan decide to run, if the electorate had the opportunity to back him or sack him. However, that underestimates the power and strength of feeling in the north that it should be their turn. In former days, that power often manifested itself in a coup d'état. Coups are out of fashion these days, even in Africa, and it is to be hoped that Nigeria will be able to sort itself out without having to have another one. There is much at stake.

Walter Blotscher