One Hundred Days is situated within a body of literature that seeks to explain the causes of international inaction during the 1994 Rwandan genocide. Cohen focuses his analysis on the United States, arguing that ‘the Rwanda genocide was one of humanity's greatest failures, with the US government leading the charge for non-intervention’ (p. 2). Cohen's contribution is undoubtedly valuable, particularly due to his use of primary sources and interview evidence. However, those hoping for analysis of the contemporary relevance of the policy failings in the US that he identifies may find themselves slightly disappointed by the narrow focus of his analysis.

In researching this book, Cohen conducted interviews with a range of individuals who influenced, or attempted to influence, US policy on Rwanda in 1994. These included representatives from the US Congress, State Department, the Pentagon, the US Embassy in Rwanda, and key figures in the Rwandan Patriotic Front, who eventually ended the genocide. The depth and range of interview material Cohen has gathered provide the strength of the book, illuminating decisions taken by key individuals within the US administration. These decisions, when taken together, account for what Cohen describes as a policy whose mistakes ‘extended beyond inaction’. Using personal testimony and declassified documents, he identifies what individuals within the US administration knew about the genocide, when they knew it, and why they did not act to prevent or end the killings. He describes a political climate in which individuals, fearing for their personal careers or believing that the Congress and the President would never authorise intervention, refused to do anything in the face of genocide, even refraining from using the term ‘genocide’ in official statements. However, he also adds depth to this analysis by considering why particular individuals did attempt to garner support for action. Cohen criticises policymakers for failing to conceive of action as anything other than military force, particularly in the early stages of the genocide. He also concludes that the deaths of eighteen US soldiers in Somalia, and the fact that Rwanda was not deemed an area of national interest, meant that ‘the metaphorical box for non-intervention in Rwanda and all other places like it was checked six months before the first machetes were drawn in Rwanda’ (p. 3).

Cohen's arguments regarding the reasons for inaction are both persuasive and well supported. However, the book could have explored further whether the failings and attitudes identified in 1994 continue to shape US policy. It is difficult to see what would have been necessary for the junior officials Cohen identifies as promoting action during the Rwandan genocide to have been heeded at higher levels of the administration. However, understanding this link is imperative if we are to understand the obstacles to effective action in the face of genocide. Cohen's analysis of why the US failed to act is detailed and accomplished. His contribution to more contemporary debates on securing international action to prevent genocide is less complete, but provides useful directions for future research.