Do politicians with a military background vote differently on military affairs? We investigate the informative institutional setting of the Swiss conscription army. Politicians who served in the military have a higher probability of accepting pro-military legislative proposals, even when controlling for party affiliations and the revealed preferences of their constituents. Although conscription requires all able-bodied man to serve at least as soldiers, we can exploit variation in exposure to enforced and voluntary service. We find evidence that intrinsic motivation to serve in the military, instead of compulsory service, plays a substantial role in explaining legislative decisions on military affairs.