In recent years, international donors have steadily increased their focus on fragile states, defined by the Organisation for Economic Cooperation and Development (OECD) as “those failing to provide basic services to poor people because they are unwilling or unable to do so”. An indication of this shift is the nature of the policies promoted by the Development Assistance Committee (DAC) of the OECD, which encourages bilateral donors that work with fragile states to adopt a whole-of-government approach, i.e. to develop cross-departmental cooperation between defence, diplomacy and development administrations. The question as to why some bilateral donors implement such integrated approaches to confront challenges in fragile states, while others only do so marginally or not at all still remains. Neither the existing literatures on security or development cultures nor the current securitization theories are able to explain the different levels and patterns of implementation of these specific OECD/DAC recommendations. In this thesis, I use the concept of “the organization of hypocrisy” to understand the complex relationship, and often the discrepancy, that exists between “talk” and “action” in the policy attempts to link security and development. Donor organizations are routinely confronted with the security and development demands of various actors. They need to act to produce results, and include such activities as contributing to UN peacekeeping missions to increase the country in question’s chances for development, or deciding who should be the beneficiaries of aid without fostering conflict. Producing these desired outcomes is not always possible however. Consequently, donor organizations “talk” about coherence, but are unable to “act” coherently and therefore to adapt their strategies and their policies. I compare France, Germany, the UK and the EU as donors – in particular in their roles in North and South Sudan, but also in selected West African countries – in an attempt to understand which factors favour a higher level of “action” with regard to the security-development nexus. I argue that bureaucracies cannot be studied in isolation from their complex and often inconsistent environment. The ability of the diplomacy, defence and development sectors to integrate their administrations and policies depends on the consistency of their environment and on their institutional ability to collectively find an acceptable convention that is capable of balancing development, diplomacy and defence norms. Protecting the normative aims of development policy is the key to achieving a higher level of integration in some OECD/DAC donor countries as well as to cultivating the formation of synergies between security and development policies.