The siege of Dien Bien Phu in 1954 long symbolized the failure of European countries to retain their overseas empires after World War II. The capture of the French base in a mountain valley in northwestern Vietnam thwarted the French effort to retain control of Indochina. In so doing, it shattered the myth of the small, elite Western force defeating native hordes thanks to the superior technology, firepower, training, discipline, and tactics that featured so prominently in narratives of colonial conquest in the previous century. In the decades following the battle, most accounts of it came from French sources that put its outcome down to lack of manpower and resources, command problems, and lack of domestic support on the French side, combined with Vietnamese human wave assaults and massive artillery bombardments.[1] More thorough research into French and, increasingly, Vietnamese sources has since yielded better estimates of numbers and resources on both sides and given due credit to the Vietnamese for their skillful tactical adjustments to given situations.[2] Valley of the Shadow continues this trend, providing the most detailed and balanced English-language account of the siege.

Military historian Kevin Boylan (Emmanuel College) has worked as a US Defense Department analyst and Luc Olivier has served in the French army and published many articles on military history. Besides the published works and archival evidence used by previous authors, they make good use of newly translated Vietnamese materials and oral history interviews Olivier conducted with French survivors. Their stated goal is to highlight the Vietnamese side of the story, while also correcting errors and oversimplifications in earlier accounts. They concentrate on the siege itself rather than reassessing the entire campaign (13 Mar.–8 May 1954). They generally accept the larger political and military context for the siege presented by other scholars.[3]

The authors first briefly survey the events preceding the establishment of the French base at Dien Bien Phu, including the mistaken assumption by most French commanders that the Viet Minh military forces lacked the resources and logistical capacity to carry out large-scale siege operations in mountainous terrain far from supply sources. In other words, they were considered incapable of interfering with the French operation of an "aeroterrestrial base" there.

The French, for their part, believed they could run offensive operations from Dien Bien Phu using their artillery and air power to repulse any Vietnamese attacks. This misconception, the authors argue, serves to explain the French failure to construct stronger defensive positions while they had the time and resources to do so. In this, they follow earlier historians. They do, however, add new information on the Viet Minh's logistical system that bears out some French assumptions regarding the challenges faced by the Viet Minh, but also shows their ability to overcome them, thanks chiefly to trucks supplied by the Chinese and a large civilian labor force.

Following earlier historians, Boylan and Olivier note that the Viet Minh commander, Gen. Vo Nguyen Giap, initially planned to storm the base in a single massive assault in late January. He decided against this owing to lack of manpower and supplies, especially artillery rounds. They credit Giap for daring to change the plan after its endorsement by Communist leadership, adducing ample statistical evidence of the wisdom of his decision. Had he attacked in January, the battle might well have gone as the French hoped it would, that is, featuring human wave assaults launched without adequate artillery support against entrenched defenders enjoying overwhelming fire support. Instead, Giap patiently husbanded his resources to mount limited attacks on the base, one strongpoint at a time, and judiciously used his growing artillery and antiaircraft assets to draw an ever-tighter ring around the core base area, which allowed him to interdict French efforts to support and supply the base by air, effectively choking it to death within two months.

The authors break new ground in several areas. In particular, they debunk claims by many French survivors that the Viet Minh overwhelmed their positions with massive artillery bombardments and human wave assaults. Boylan and Olivier use Vietnamese records to show that comparatively fewer men were in action and less ammunition was used during assaults on individual French strongpoints. Through most of the siege, the French were better supplied with artillery rounds than their opponents and often expended more shells in resisting attacks than their enemy did in conducting them. The Viet Minh in the surrounding hills were better able to locate and hit their targets; moreover, the poor quality of many French fortifications made them vulnerable to destruction by even a few direct hits. This likely explains the defenders' exaggerations of the scale of bombardments they faced. Similarly, the Viet Minh made the most of their nighttime attacks by concentrating their forces on positions where they could achieve numerical superiority, duping the defenders into thinking they faced more enemy troops than they actually did.

The authors also stress the ability of Giap and his subordinates to adapt their tactics to counter the strengths of the French. One stereotype of the Vietnamese in both their French and American wars is that their top-down command structure hampered improvisation by subordinate commanders, let alone common soldiers, in the midst of a battle or campaign. The authors cite plenty of examples of mission failures after the loss of commanders. In some cases, this resulted from unit commanders adhering to orders instead of adapting to the specific situations confronting them. One notable contrary example comes in the authors' account of a night attack on the strongpoint Huguette-1 by Pham Hong Son's 36th Regiment (22–23 Apr.). Son's men had been digging World War I-style trenches closer and closer to the French positions. Son dealt with his troops' fatigue by rotating them in and out of digging assignments, while deploying most of them to fend off French counterattacks. He also called in brief bombardments several nights in a row to make the French think an attack was coming; he even had his men follow the barrages with shouts of "Assault!"—all to throw off the defenders.

The attack proved highly successful; in fact, the whole position was overrun in a couple hours with minimal casualties. Not only was the initial attacking force tiny, but its preliminary bombardment expended just thirteen 105mm shells. The French artillery had no means of responding and did not fire at all. Son's "creeping siege" tactic was used successfully in future assaults (197).

The authors also address the question of the quality of the defending troops of Dien Bien Phu. They were not primarily the battle-hardened paratroopers and Foreign Legionnaires typically associated with the defense of the base, but colonials—mainly Moroccan, Algerian, and Indochinese. Nonetheless, French authors tended to emphasize the actions of French troops and French commanders of non-French units; they generally discount the quality of the latter, especially the Vietnamese. To be sure, Boylan and Olivier note instances of desertion, panic, and demoralization among such soldiers, but they also highlight largely ignored instances when they fought well.

While Valley of the Shadow makes a significant addition to the literature on Dien Bien Phu, it falls somewhat short of its main goals. Boylan and Olivier draw astutely on new Vietnamese materials, especially regarding troop strengths, availability of artillery, and antiaircraft pieces and ammunitions supplies. They add details to Vietnamese accounts of various parts of the siege. But their overall account of the siege and its outcome differs little from that of other recent studies.

In the end, most of the book is founded on familiar French accounts, apart from the interviews Olivier conducted with French survivors, which illuminate matters other authors have elided or glossed over. Other books offer better background on the construction of the base and the larger context of its siege within the war at large.[4] Consequently, these may be better staring places for readers unfamiliar with the topic. But Kevin Boylan and Luc Olivier have provided the most accessible and convincing analysis of the siege itself.