This article proposes Stephen Jay Gould’s concepts of time’s arrow and time’s cycle as a conceptual tool to analyse NATO’s burden-sharing disputes. It argues that the controversies on burden-sharing in NATO can be assessed in terms of their cyclic or arrow kind nature, rendering some disputes more likely to recur than others and providing different kinds of starting points for their forecasting. The study identifies four cyclic categories in which burden-sharing has transformed into a political debate among NATO members during the post-Cold War era: geopolitical change related to Russia; periods of US foreign political retrenchment or renewal; the passivity or activism of European NATO members; and during NATO or allied out-of-area operations. Moreover, the study suggests an arrow kind of direction in burden-sharing disputes, indicating an expansion of disputes to cover comprehensive security, resilience, security co-operation and diplomacy, and to engulf also NATO partner countries.