For a generation, Commonwealth summits provided a regular forum for the adoption of indignant declarations against the crimes of apartheid. Many members, who had emerged from colonialism with bitter memories, felt that the compelling need for solidarity against South Africa meant that it was undesirable to look too closely at the political systems in other African countries.
As a result, the summits became overloaded with emotion and the scenes of confrontation between Margaret Thatcher and her Third World detractors became a predictable source of entertainment.
All that has changed. "There is now a common bond of democracy," a senior British official said. "Ever since the Commonwealth stopped fighting over South Africa there has been a question about what you do at its conferences. The issue now is military rule - you should not automatically assume that military dictators will be welcome at your conferences."
Last week Baroness Chalker, the Foreign Office Minister responsible for Africa, launched a strong attack on the military regime in Nigeria and said its leader, General Sani Abacha, would probably not be welcome at the next summit. "It has become clear that Nigeria cannot play a full role in the Commonwealth until it puts its house in order," she said firmly. Only "a rapid and credible timetable for the transition to civilian rule" could ensure General Abacha would be welcome in Auckland.
The immediate reason for outside concern over Nigeria is a secret tribunal set up by the military government to hear charges of sedition and plotting a coup against a group of defendants drawn from the opposition. The former head of state, General Olesegun Obasanjo, is reportedly among those who are facing trial.
"He is the only military ruler who has ever returned Nigeria to civilian politicians," Lady Chalker said. "These proceedings are quite unacceptable."
Two other African Commonwealth members, Gambia and Sierra Leone, are also under military government. But the Nigerian crisis goes to the heart of the Commonwealth because it involves Africa's most populous country, a nation of great economic potential that was a standard-bearer in the crusade against apartheid.
In 1991, recognising the changes afoot, Commonwealth members meeting in Harare adopted a declaration pledging to work with vigour for "democracy . . . and institutions which reflect national circumstances, the rule of law and the independence of the judiciary and just and honest government".
The trial in Nigeria is a conspicuous affront to the principles of the Harare declaration. It comes after two turbulent years in Nigerian politics which have seen civil unrest and strikes in the vital oil industry. In 1993 the military authorities annulled a general election that was supposed to have ushered in a civilian government. A businessman turned politician, Moshood Abiola, declared himself the winner of the election and later proclaimed himself president. He was promptly put in detention. Opposition groups see the latest trial as another attempt to stifle calls for a return to democracy.
The Secretary-General of the Commonwealth, Chief Emeka Anyaoku, is himself a Nigerian but says this does not inhibit him from speaking out. "I have watched with alarm the country's drift towards a self-inflicted tragedy," he says. "I have said again and again in public, and privately, that there is no place for the army in the politics of any Commonwealth country."
Optimists in the Foreign Office see it as a sign of maturity that African and Asian nations once united in their abhorrence of white South Africa are ready to turn their attention to the misdeeds of a leading African member. And in a final twist of irony, many are hoping that it will be the South African President, Nelson Mandela, who intervenes to persuade Nigeria's military dictators that their continued rule is unacceptable.