Why has NATO taken so long in adapting its deterrence strategy to Russian revisionism and extending its military presence to the eastern allies? The setting up of Enhanced Forward Presence (eFP) in Poland and the Baltic states offers a critical case for examining the changing understandings of allied deterrence in the post-post-Cold War era. eFP is a story of negotiating the political acceptability and military credibility of NATO’s modern extended deterrence strategy in the exposed eastern flank, and the navigation of the alliance security dilemma in relation to Russia. Drawing on the first phase of fieldwork of my ERC RITUAL DETERRENCE project (https://ritualdeterrence.eu), I trace NATO’s extended conventional deterrence posture in the eastern flank from the adoption of the tripwire model shortly after Russia’s annexation of Crimea to the commitment to defend ‘every inch of Allied territory’ via embracing the forward defence stance in 2022. Mapping the evolution of NATO’s post-enlargement politics of deterrence through documentary analysis and interviews with diplomats, military representatives and various experts, the paper makes two contributions. Conceptually, it dissects the political rationalities and historical analogies underpinning contemporary allied deterrence strategy and posture in NATO’s eastern frontline. Empirically, it illustrates how allied deterrence is made to matter on the ground, and why this matters for its credibility. NATO’s eFP on the Alliance’s eastern flank illustrates how ritual performances of deterrence seek to enhance the credibility of extended deterrence posture and messaging.