War stretches human endurance to its limits, both for those at the sharp end of combat and for the generals on whose decisions turn the fates of their forces and their homelands. The pressure on commanders and the consequences of any psychological function make for fascinating material, which Pois and Langer explore in their collection of accounts of notable command failure. There is no particular logic to the case studies (three out of eight are from the U.S. Civil War), and the conclusions are inevitably speculative. Inflexibility, overreliance on familiar strategies, and underestimating enemies can have causes that are as much institutional as they are personal.
There is a similar problem with Rosen's much more ambitious book, which seeks to draw on recent advances in neuroscience to advance our understanding of how key decisions on war and peace are made. Any book that challenges the dreary influence of rational choice theory on the study of international relations is to be welcomed, and Rosen rehearses the well-known limitations of the rational-choice approach, including the qualifications based on experimental psychology, with the refreshing enthusiasm of the recent convert. He has sufficiently mastered a complex area of scientific inquiry to convey key findings in a comprehensible and interesting way. But there is a large "so what" question, especially since Rosen is no biological determinist: can the new science really support an improved understanding of political and military behavior? It arguably can when considering what happens to soldiers in combat, but when it comes to individual decision-making the importance of circumstance is often overriding. When an individual has accumulated supreme power, personality becomes more relevant, which is why Rosen's final chapter concentrates on tyrants; one wonders whether a deep understanding of the human brain was necessary to work out that such people are obsessed with status and not always receptive to information.