There is no link to the article, but here is a link to the Marginal Revolution post that cited it and also an opinion from economist Tyler Cowen that his issue is that he does not think the foreign aid would end up in the hands of the poor in these cases.
Our research find that a 5% drop in per capita income due to drought increases the likelihod of a civil conflict [in African countries] in the following year by nearly one half. That's a very large effect.
...Currently, most foreign aid focuses on long-term investments in infrastructure of education but does little to deal with such short-term triggers of violence as drought or falling export commodity prices. But our research suggests a larger share of aid should aim to dampen the sharp falls in income that actually generate recruits for rebel movements.
(Source: Marginal Revolution)