Leading article: When harmony strikes false note

Two years ago, the last Commonwealth summit in Ajuba was dominated by Zimbabwe. But the deep split over the response to Robert Mugabe's thuggery at least suggested there was life still in what is often dismissed as a talking shop of former British colonies. That this year's summit in Malta promises to be quieter may therefore be ominous, raising the old question of what it's all for.

If no "row" ensues, however, it will not be for lack of a worthy cause. Zimbabwe has been suspended, so there's no danger of the Queen or Tony Blair risking an embarrassing personal encounter with Mr Mugabe. But it will be shaming if that is the end of the matter. This is, after all, a regime that aid organisations have accused of using food aid as a weapon against its own citizens - a crime that cries out for investigation.

And among those clinking glasses with the Queen, several have rotten human rights records. President Yoweri Museveni of Uganda may be a favourite of the West for his hard-nosed economics, but the arrest of Uganda's opposition leader, Kizza Besigye, warrants unambiguous censure, not emollient words from Mr Blair.

And Pakistan's Pervez Musharraf is still in uniform, breaking his own pledge to restore the country speedily to civilian rule. Among the 53 countries represented, many are near the top of Transparency International's Index on Corruption. Yet corruption - a glaring evil in developing countries - is unlikely to be raised. So no row there either.

In a world split more than ever between the West and the rest over terrorism, aid and the environment, the Commonwealth could be a useful forum, where Third World and Western countries meet on a genuinely equal footing. Idiosyncratic as are the membership criteria, the way the Commonwealth harnesses three members of the European Union, Canada and Australia to African and Asian states, lends it - potentially - moral authority to speak out on issues such as disaster relief, which more exclusive or more geographically and economically homogenous clubs don't possess.

Sadly, a desire for instant bonhomie seems to prevail. The Queen and Tony Blair may leave Malta relieved to have been spared conflict. If so, it will be for all the wrong reasons.