Dictators depend on a committed bureaucracy to implement their policy preferences. But how do they induce loyalty and effort within their civil service? We study indoctrination through forced military service as a cost-effective strategy for achieving this goal. Conscription allows the regime to expose recruits, including future civil servants, to intense 'political training' in a controlled environment, which should improve system engagement. To test this hypothesis, we analyze archival data on over 370,000 cadres from the former German Democratic Republic (GDR). Exploiting a natural experiment generated by the introduction of mandatory service in the GDR in 1962, we find a positive effect of conscription on bureaucrats’ system engagement. Additional analyses indicate that this effect likely did not result from deep norm internalization. Findings are more compatible with the idea that political training familiarized recruits with the elite preferences, allowing them to behave strategically in accordance with the 'rules of the game.'