Executive Summary
Multi-Domain Deterrence: Coherence Under Pressure.
Magda Maszczynska, Deterrence Center, 2026
Western states and alliances possess more deterrence tools than at any point in history. Yet adversaries continue to erode deterrent effect with increasing confidence - not by confronting military strength, but by exploiting the fragmentation between domains, institutions, and allies that Western deterrence architecture has left unaddressed.
This paper argues that coherence is the primary determinant of deterrence effectiveness - not the magnitude of power, but the consistency and alignment with which that power is expressed across military, civilian, informational, economic, and societal domains simultaneously. This produces a fundamental inversion: it is not power that generates deterrence effect, but the coordinated expression of power across a multi-domain system. Capability without alignment is strategically discounted. Fragmentation is not a weakness at the margins. It is the primary attack surface.
A comparative analysis of all thirty-two NATO member states reveals that the Alliance shares a common grammar of deterrence but not a common semantics. Commitments are genuine. Operational alignment is not. Deterrence today is multi-domain in practice but not in design - episodic where adversaries are continuous, fragmented where adversaries are integrated, and reactive where the strategic environment demands architecture designed in advance.
Three original contributions follow from this analysis. The coherence over power inversion reframes how deterrence effectiveness should be measured and designed - less by counting capabilities, more by assessing the degree to which those capabilities remain aligned and mutually reinforcing under pressure. Collateral Deterrence Pressure names and analyses the systemic vulnerabilities generated in third-party states as unintended consequences of deterrence actions between primary actors -a variable the field has not yet adequately addressed, with direct implications for alliance management and the design of economic and technological pressure instruments. The Structured Unpredictability Framework proposes that democratic alliances can harness unpredictability as a deliberate deterrence tool without sacrificing coherence, provided core commitments remain fixed while ambiguity is preserved across the form, timing, and domain of response.
Together, these contributions form the foundation of Multi-Domain Deterrence - a framework that reconceptualises deterrence not as a military posture or crisis instrument, but as a system condition emerging from the coordinated interaction of capabilities, institutions, and societies across domains under pressure.
The practical implications are immediate. Deterrence must be institutionalised as a continuous system condition, not a crisis response. Intelligence must sit at the centre of alliance coherence, not at its margins. Resilience must be understood as an active deterrence signal. Narrative coherence must be treated as an operational domain. And error management - preventing miscalculation under uncertainty - must become as central to deterrence design as capability development. The adversary does not probe strength alone. It probes coherence. Fragmentation invites testing. Coherence raises thresholds.