Why Military Deterrence Fails Against Terrorism: Evidence from a Cross-National Analysis, 2011–2021

Drawing on deterrence theory, the War on Terror institutionalised a security framework centred on the use and threat of force as the primary means of addressing terrorism. Its core premise — namely, that increasing the threat of coercion necessarily produces stronger deterrent effects and greater compliance — has, however, rarely been questioned. Challenging the assumption of perfect rationality implicit in the presumed linearity between ‘severity’ and compliance, critics argue that the threat of ‘maximum coercive power’ embedded in militarised interventions may fail to achieve its intended aims and instead generate backlash effects by eroding legitimacy and placing non-state actors in a ‘loss frame’, thereby increasing risk acceptance, incentives for violent retaliation, and organisational adaptation. By contrast, governance-enhancing, non-violent interventions are expected to situate actors in a ‘gains frame’, thereby reducing incentives for mobilisation.This article examines whether higher levels of militarisation are associated with reductions in terrorism, whether they are counterproductive, or whether governance-centred, non-violent interventions are more effective. Using cross-national data from 2011–2021 and employing Poisson pseudo–maximum likelihood models with country and year fixed effects and robust clustering, the study finds no evidence that militarisation deters terrorism, limited evidence of backlash, and strong evidence that governance-oriented interventions significantly reduce terrorist activity. These findings challenge the policy assumption that greater coercive capacity enhances security and instead suggest that governance-centred approaches may offer more effective and sustainable counter-terrorism strategies.