A new Thucydides Trap? How traditional defense buildups can exacerbate contemporary power decline

The Thucydides Trap describes the tendency for power transitions to culminate in war. The dominant power’s fear of displacement prompts defensive buildups which can spiral into armed conflict. The historical recurrence of this pattern has raised concerns about the US-China rivalry today. This article suggests that contemporary realities make the classic Thucydides Trap less likely, but instead set a new Thucydides Trap: the danger that instinctive defense buildups induce strategic imbalance. In the modern era, where geopolitical influence is shaped less by coercive force and more by leadership in enabling technologies and supply chains, traditional defense buildups carry real opportunity costs. The article employs a longitudinal case study of US discretionary spending over the past three decades that shows how American prioritization of defense over industrial-technological investment inadvertently facilitated Chinese advances in key four domains of contemporary geopolitical weight: rare earths, solar photovoltaics, batteries, and science and technology leadership.