Mugabe was cheered when he said this:
While the sadistic scenes from Abu Ghraib remain vivid in our minds, other places in Iraq and Guantanamo Bay have provided useful samples of the Western concept of respect for human rights. Let me say once again that the West should spare us their lessons on human rights. They do not have the moral authority to speak about, let alone, parade themselves, as torch-bearers of human rights.
http://www.un.org/webcast/ga/59/statements/zimeng040922.pdf
The first risk it that Mugabe will polarize public opinion in the West against him. Even though Blair's government seeks to remove him from power, and the US is going along, there's no popular mandate for taking action in Zimbabwe, at least among the US public. The safe course for Mugabe would be to let people remain indifferent. By ratcheting up the rhetoric, landing a few jabs while portraying himself as the West's punching bag, he may indeed end up becoming the West's punching bag. The excellencies who cheered Mugabe's defiance may be of the sort who are inclined to cheer any leader who dares stand up against the West, but are not inclined to intervene should it come to blows, especially not in the defense of a petty tyrant.
The second risk Mugabe took, which wasn't quite reported in the story, is that he lent legitimacy to the African Union mission in Sudan, which is essentially a case where the organization is putting human rights above the interests of national sovereignty (although Sudan is of course a member of the AU and therefore has chosen to abide by its rules). Does this contradict Mugabe's spirited critique of the UN's shift towards protecting universal human rights and redefining the limits of sovereignty? Fundamentally I think it does Be that as it may, if Mugabe wants to submit to a specifically African regime of international human rights, then he risks inviting an AU intervention in Zimbabwe's affairs. So far the AU has handled Zimbabwe with kid gloves. If Mugabe proves to be terribly wrong about his government's ability to feed people, of if he continues down the road of draconian intollerance, he could well find himself at the top of the AU's agenda with more powerful African nations pressuring him to step down.
Why is he running such a risk? Perhaps he is calculating that if he can present himself as a popular voice of African nationalism (and anti-Americanism) he can undermine the legitimacy of any moves against him within the AU. That's not intended to disarm directly the major powers like Nigeria or South Africa, but it could win him allies among weaker states, and those alliances could be enough to ward off any intervention.
That's my two cents.