William Easterly says:
I confess that I am still moved as much as anyone else by the compassionate case for saving civilians from horrific violence. But we have to ask the tough questions: Even if the war proceeds from humanitarian motives, does it actually have humanitarian consequences?
This question arises in Easterly's review of Paul Collier's book The Bottom Billion:
These may sound like arcane statistical debates when you are trying to decide whether to save a poor country. But if you are going to recommend military intervention based on social science research—in short, if you are going to read Collier's book and draw conclusions from it—then you have to face up to the technical fallacies that may lurk behind research findings.
Alas, we have now seen two common fallacies appearing in the book, "correlation equals causation" (which spuriously concluded that UN peacekeeping forces cause peace) and "selection bias" (which made it appear that the Bottom Billion were trapped in low income and low growth, when no such conclusion is established by historical evidence).
Bill ... takes aim at the melding of foreign aid and military intervention over the past decade.
One should never say never—there may be cases where foreign forces can rescue innocents from horrors. But as generalized doctrine, as Alex de Waal says eloquently, "philanthropic imperialism is imperial nonetheless." In the end, one cannot hide all the political and ethical complexities of foreign military intervention behind a neutral façade of Collier-type statistical analysis. The hubris of the military imperialists was bad enough without adding to it the hubris of the aid imperialists.
...I'm worried that Bill's advice will be taken too literally and simplistically by those who would advocate a divorce of the humanitarian and the military. ... In short,... let's not take Collier as the definitive word on foreign aid and military intervention.
Look instead to scholars like Page Fortna and her new book, Does Peacekeeping Work?. Page's work is among the best I have read on post-conflict stabilization. She moves from cross-country statistical analysis to deep and insightful analysis of specific missions: Sierra Leone, Mozambique, and Bangladesh. International intervention dramatically reduces the risk that war resumes, she argues, because of the change in incentives, perceptions and institutions it engenders. Surely peacekeeping is no panacea, but it certainly helps to learn when and why it works.