the germ theory of intervention

Christopher Hitchens says that if a country's policies are so bad that it's leading to disease that is then transmitted across borders, that's grounds for international intervention. And, because of the cholera outbreak, we should invade Zimbabwe.

Zimbabwe is undeniably a tragically collapsed state, a breadbasket turned into a basket case, and that is directly a result of Robert Mugabe's policies. To me, though, Hitchens doesn't have much of a case. The precedent that such an intervention would set would be so broad as to basically undo all sense of sovereignty. By rights, South Africa should be next because of its dithering policies on AIDS, which have helped fuel the spread of the disease across the subcontinent and beyond. Dozens of developing countries that for either political, ideological, religious, or infrastructural reasons are unwilling or unable to deal with dangerous diseases, be it malaria or AIDS or polio or avian flu or even SARS, could justifiably be subjects for "intervention." Hell, the most recent cholera outbreak to make the news before Zimbabwe was in Iraq... AFTER the US invasion. What were we supposed to do? Invade again and liberate the country from ourselves?