This study takes a closer look at the adoption of the U.S. military concept of network-centric warfare (NCW) by the British and the German armed forces. The book uncovers the striking differences between NCW adoption in the UK and in Germany in terms of timing, pace, concept faithfulness and implementation. Relying on the process tracing technique and framed by an institutionalist argument the study establishes that a different composition of efficiency/effectiveness and legitimacy-related drivers in the two cases can account for the different adoption outcomes. In the case of NCW adoption, the British military was an efficiency maximiser whereas the German military was a legitimacy maximiser.