In chapter three, we examine the impact of the growing geopolitical tensions of the 1960s on the North Korean developmental model. The emerging Sino-Soviet split raised important questions regarding the reliability of North Korea’s socialist allies and further strengthened the impetus towards autonomous heavy industrialisation and the building of a strong independent military industrial sector. Furthermore, these geopolitical challenges were exacerbated by the establishment of a strong military regime in South Korea and the latter’s own national project of catch-up industrialisation. As a result, the negative economic consequences of militarisation became increasingly visible in the 1960s. This chapter also examines the emergence of Juche as the ruling state ideology in North Korea. Here, we engage with the existing literature on the topic by reinterpreting Juche as a particularly intense form of developmental nationalism aimed at legitimising the human mobilisation required to facilitate catch-up industrialisation. From the late 1960s, Juche thought was further transformed as an ideological justification to strengthen Kim Il Sung’s monolithic system, and as such, the previous emphasis on post-colonial catch-up development was diluted. Here, we draw parallels to the voluntarism of Stalinist and Maoist ideologies while highlighting the distinctiveness of this North Korean form of developmental nationalism.