This contribution examines the decline of Belgian military criminal law in the two decades following the abolition of military courts in peacetime (2004). Historically, maintaining good order and discipline in the Belgian Armed Forces was done via three mechanisms: military criminal law, operational discipline, and statutory discipline, all aimed at maintaining good order and discipline within the armed forces. While the Military Criminal Code remains formally in force, its practical relevance has sharply diminished. Statistical analysis reveals a 75% decrease in reported martial offences between 2005 and 2024, with convictions becoming exceedingly rare. This trend predates the abolition of military courts and could be explained by broader sociological and institutional developments: the professionalisation and downsizing of the armed forces, the suspension of conscription, the civilianisation of the military profession, and evolving operational contexts that favour flexibility over rigid obedience. The contribution argues that these factors have shifted reliance away from criminal sanctions toward disciplinary measures. However, recent geopolitical instability, notably Russia’s invasion of Ukraine, may revive the need for robust enforcement mechanisms, especially if conscription returns. The authors conclude that while military criminal law still serves a complementary role, it requires modernization and harmonization with disciplinary systems to remain effective in the 21st century.