The opening session of the 13th African Union summit in Libya has been marked as much by what didn't happen as by what did. A scheduled appearance by Iranian President Mahmoud Ahmadinejad was abruptly cancelled.

The substance of this summit on Libya's Mediterranean seacoast has been largely overshadowed by the personalities attending, and those who are not.

News on the eve of the meeting was that Iran's President Ahmedinejad had been invited. On opening day, the headline was that Mr. Ahmedinejad had abruptly cancelled because of what were called program priorities.

Some western and African diplomats are known to have privately expressed annoyance at the Iranian leaders' attendance, saying it would have been a distraction from the summit's important business.

The host, Libyan leader Moammar Gadhafi made no mention of Mr. Ahmedinejad's absence in his brief opening address. Instead, he issued a call to Caribbean countries to join the union, saying their people are Africans.

Other big name cancellations included Italian Prime Minister Silvio Berlusconi and Egyptian President Hosni Mubarak. Among those who did show up to share the spotlight with Mr. Gadhafi were Brazil's President Lula de Silva, who took advantage of the occasion to denounce the coup in Honduras. African notables included Sudan's President Omar al-Bashir, Zimbabwe's President Robert Mugabe and South African President Jacob Zuma.

The scene prompted some commentators to recall the bad old days when the AU's predecessor, the Organization of African Unity, was known as the Club of Dictators. But veteran AU observer Kenneth Mpyisi of the Institute of Strategic Studies says despite the appearance, the majority of members remain committed, at least in principle, to democratic values.

"When you really look deeper at what the AU is doing and what is happening at the regional economic community level, though the progress has not been what we might have expected a number of years ago, it has changed, and it is a work in progress, and next year this time we might be talking about the next summit within a very different context if we are looking at the political leadership of the day," he said.

There was news during the day. A statement announced the lifting of sanctions against Mauritania. The AU Peace and Security Council had imposed the sanctions, and suspended Mauritania's membership in the union last August, after the army overthrew the elected president.

This three-day summit is due to address other continental hot spots where the outcome remains in doubt. Among them are Somalia, where the transitional government is under siege by hardline Islamic rebels, Guinea and Guinea Bissau, Madagascar and Darfur.

Mpyisi says the union is a mixed bag of failed states, countries struggling with democracy, and success stories. "Earlier this year we were talking about the successes of Ghana, Botswana had successful elections, Zambia which had successful elections. When you have others countries which we have already mentioned, and their problems. The real issue lies in how much attention and how much consistency and perseverance we put in strengthening democratic institutions because what we are seeing is we are paying the price for not having paid enough attention to the issues we know are very significant, which is governance and developing and strengthening democratic institutions," he said.

The summit's mostly closed door sessions are taking up several thorny issues, among them a proposal to create an African Defense Council. Establishment of the council would be a step toward Mr. Gadhafi's concept of a united Africa.

Diplomats say heads of state are sharply divided over the issue. But those in favor and those opposed seem to agree on one thing: the matter must be settled quickly so it doesn't hang over the AU agenda, taking up valuable time at summits for years to come.