World War I is commonly perceived as having had a profound impact on international law. Such a general perception, be it justified or not, might in any event prove erroneous when looking at specific areas of this law. A focus on the law governing military occupation reveals a notable absence of change over the course of the war and the subsequent interwar period. In search of possible reasons, this article first looks at various opportunities that emerged – but were not ultimately seized – to adapt treaty law in the period between the two world wars. It then assesses whether changes had in fact occurred through other channels such as customary international law or treaty interpretation. Based on the observation that no meaningful change intervened, can it be concluded that, on the whole, the Hague regulations on military occupation met stakeholders’ expectations and therefore were not altered? The author suggests, rather, that the equilibrium founded in The Hague in 1899 (and confirmed in 1907) on the lines of tension between the states involved remained operational throughout the period under scrutiny.