This thesis examines British national security decision-making. It does so by using a theoretical approach that provides several different perspectives on the nature of the institutional environment and its effect on decision-making. This environment is essentially bureaucratic, and is formed from a group of security-related bureaucracies that have routine connections with each other, and with certain International Government Organisations and other states and their bureaucracies.

The thesis begins by defining the ways in which bureaucracies are formally designed and decision-making processes are expected to occur in a rational way. It then introduces three theoretical constructs – based in an extension of Weber, Bourdieu and Sociological Institutionalism – to demonstrate how the formal design of bureaucracies and decision-making processes are undermined by rational pathologies, struggle and institutional conformity. Grounded in extensive ethnographic research, it does this by examining current security practices and a relatively recent national security decision. This decision is the British and North Atlantic Treaty Organization (NATO) decision to expand across Afghanistan and implement a highly ambitious nation-building project between 2003-2006.

The thesis centrally argues that, despite bureaucracies being organised to produce them, truly instrumental decisions are a rarity for three primary reasons. First, decisions are frequently undermined by problems associated with the domineering nature of bureaucratic behaviours and institutional forms of rationality. Second, struggle routinely animates the environment, which leads to the constitution of internal security logics and compromised decisions. Third, highly connected Western bureaucracies are increasingly similar in structure and ideas, and the processes that lead to this homogenisation often create dysfunction and result in ill-considered decisions and security applications.

Reflecting on what this evidence means, the thesis concludes by attempting to define the nature of the environment, rationality and the consequent implications for strategy and war. It argues that evidence of the theoretical constructs should be seen over time as entwined social processes; that a plurality of rationalisation processes not only undermines instrumentalism but makes the environment seem more “rational”; and that the Western way of war is evermore bureaucratised and technically ordered, but evermore unthinking, inflexible and problematic.