In Defect or Defend: Military Responses to Popular Protests in Authoritarian Asia, Terence Lee's goal is to understand why some popular protests in Asia have led to the collapse of authoritarian regimes while some regimes have been resilient, quelling protests and tightening their grip on power. Lee asserts that an authoritarian regime's capacity to survive popular protests rests on two factors: a lack of personalism among its leaders and, as a consequence, the support of the nation's military forces. Lee defines personalism as “the degree to which decision making and coercive power is concentrated in the hands of one person” (p. 38), and it is this phenomenon that leads dictators to lose the support of key military allies. Lee uses four case studies in his analysis, two of which led to democratic change, and two of which did not. The fall of President Marcos of the Philippines in 1986 and President Suharto of Indonesia in 1998 are both attributed to personalism, leading to democratic transitions in both countries. Lee's other two case studies are instances in which authoritarian regimes that clearly avoided personalism were able to survive massive protests: China in 1989 and Burma in 2007.

Lee's approach to authoritarianism has its strengths and weaknesses. As he recognizes repeatedly in his work, using only four case studies and focusing exclusively on Asia limits his theoretical credibility. Lee admits that his four case studies can only serve as a starting point for theory generation rather than theory testing itself. His work provides for no wider statistical verification, but that is not the author's intention. Lee's theories are also difficult to apply elsewhere. He speculates that conditions that did not apply in Asia, such as ethnic factionalism, may have allowed for personalist dictators, like Bashar al-Assad in Syria, to maintain the military's loyalty, which has allowed them to avoid transitioning toward democracy even in the face of widespread protests. Thus, Lee's theories on personalism, while compelling in his specific case studies, may not be nearly as applicable to regime transitions in other regions or in the future. Lee even recognizes that his theories cannot be applied well to the Arab Spring, nor do they account for many of the post-Communist transitions in Eastern Europe.

Beyond some of the author's self-admitted qualifications, however, is a very compelling narrative, and Lee's case studies are exceptionally well written. His focus on Asia alone also has its benefits, especially in being able to make a direct comparison between dictators and their regimes. The key to successful popular protests, according to Lee, is the military's response. When the armed forces choose to back civilian protestors over dictatorships, an authoritarian regime will find it impossible to survive, at least in its current form. As Lee notes in his introduction, when militaries defect, mass revolts are 46 times more likely to succeed. Thus, having established that military revolts are essential for regime change in protest situations, Lee's major question is why militaries defect in some situations and not in others. The answer, according to the author, is personalism within the armed forces.

In the cases of both the Philippines and Indonesia, personalism within the military led to growing factionalism, and, when popular protests erupted, personalism and the dictator's direct interference in military affairs motivated unhappy senior officers to abandon the authoritarian regime and ally with disillusioned domestic civilian forces and major figures in the local opposition movement. Personalism creates winners and losers, leads to internal competition, and alienates vast portions of the military. In the Philippines, the anti-Marcos coalition grew out of the Catholic Church, businesses, domestic opposition, American support for change, and, ultimately, defections from within the military. In Indonesia, Suharto's nepotism, military factionalism, and senior military defections were the crucial factors in the regime's fall from power in 1998. The key to the survival of the authoritarian regimes in China and Burma was the fact that personalism was non-existent within the regime. This allowed both nations’ leadership to foster loyalty and support from their armed forces, leading the military to agree to repress massive protest movements. In China and Burma, the regime was organized around power-sharing institutions which were specifically designed to avoid personalism. In these situations, the dictator and his ruling elite commit to joint rule. This was seen in China through the Communist Party's state apparatus and in Burma through the military junta.

Lee makes an important contribution to the field because, as he notes early on, theories on authoritarian breakdown have downplayed the importance of popular mobilization. Moreover, few theorists recognize the important role that the military can play in allowing popular demonstrations to succeed by withdrawing its support from the authoritarian regime at such a crucial time. Authoritarian leaders are very much reliant on support from the military to remain in power, and personalism and military factionalism in the Philippines and Indonesia were responsible for the regimes’ collapse. Despite the fact that Lee's work may not be directly applicable in other regions or time periods, the link he forges between personalism, protest movements, and military defection is an important one.