The history of much of mainland Southeast Asia has been, before the modern age, one of under-population and the inability of kings to establish effective control over regions remote from their directly-held power bases. One of the principal shaping forces of that history has been the terrain – thickly forested, mountainous with river valleys – which has been so habitable to mosquitoes. And where there are mosquitoes, of course, there is malaria. Malaria has been one of the biggest killers of mankind throughout history and countless millions of lives have been needlessly lost to it and, indeed, still are. In the twentieth century, it appeared that malaria was being brought under control as newly developed drugs proved more or less effective in curing it or preventing it one way or another (when I lived in Sudan, it was the case that foreigners such as myself could be kept safe because the drugs would be effective for a limited period but full-time residents would not because drug effectiveness would not last – people died from malaria while I was living in Kassala and others were seriously ill). In Thailand and neighbouring countries, the massive deforestation caused by the thirst for the income provided by teak and hard woods had the side effect of reducing the habitats available for the mosquitoes and was an important reason for subsequent population growth. Unfortunately, resistance to drugs increases in living species as we are forced to accept the negative consequences of evolution: the mosquitoes along the Thai-Cambodian border, for example, seem to be becoming fiercer and more resistant. The problem is intensified by the widespread prevalence of substandard or counterfeit drugs, which are weaker and presumably easier for the vile yung to shrug off. As ever, it will be the poor and the vulnerable who are likely to suffer most from this, since they live in the more dangerous rural areas and have fewer opportunities to access high quality medical care.