Deter. Fight. Win. Together.

Why national and alliance leaders are redefining readiness for an era of contested multi-domain operations.

Deter. Fight. Win. Together. Four words that framed the first major speech of the UK’s Chief of Defence Staff, Air Chief Marshal Sir Richard Knighton, at DSEI UK 2025. They are not just a slogan, but a challenge: to ensure forces are prepared to act at pace, across domains, and in lockstep with allies.

Knighton’s emphasis on speed and adaptability echoes a wider truth recognised across NATO: deterrence and mission success now hinge less on mass and more on agility, resilience, and the ability to adapt faster than adversaries.

Deterrence only works when readiness is visible, credible, and joint; warfighting only succeeds when decisions and actions move at the speed of relevance. To deter, fight, and win, each nation must bring its full capabilities to bear — but to do so together demands something greater. It requires trust between allies, seamless coordination between domains, and sovereign resilience in the face of disruption.

The Strategic Imperative for Multi-Domain Interoperability

Taken together, the messages from DSEI underline a new operating standard: NATO and its partners must deter, fight, win, and do so together. This is not aspirational rhetoric — it is a practical demand shaped by lessons from Ukraine and the realities of today’s contested security environment.

Deter

Deterrence today is not just about mass or firepower, it is about credibility. Ukraine has become a “crucible of change” — proof that the ability to adapt faster than an adversary generates a deterrent effect. For NATO, this means integrated coalitions able to mobilise rapidly, share intelligence in real time, and present a united front across land, sea, air, space, and cyber. To deter is to demonstrate interoperability at speed.

Fight

NATO must now prepare for operations in contested environments, where logistics, airspace, and cyber domains can no longer be taken for granted. Fighting in this context demands multi-domain coordination at unprecedented tempo, with systems that can absorb shocks and still deliver mission assurance. To fight effectively in the 2020s and 2030s is to integrate sensors, shooters, and decision-makers across coalitions — without delay, without stovepipes, and without compromise on sovereignty.

Win

History shows that wars are rarely won quickly. If NATO cannot achieve a decisive victory in the opening phase, it must be ready to sustain the fight and adapt over the long term. Winning requires resilience — the ability to continue operating in degraded, disrupted, or denied conditions while maintaining the agility to innovate faster than the adversary. The critical test is to ensure resourcefulness translates into readiness, and readiness into resilience — so that ingenuity is not just demonstrated, but sustained at scale.

Together

Of the four words, together may be the most important. No single service, nation, or industry partner can deliver deterrence or victory alone. Together means coalition trust, secure information-sharing, and industrial ecosystems that operate at wartime pace. It also means rethinking defence–industry partnerships: opening architectures, simplifying approvals, and valuing time as much as cost. Unity ensures allies can act as one, at speed, and at scale.

The Current Gaps in Defence Sovereignty and Interoperability 

Despite the urgency of this framing, today’s systems and processes still fall short. Defence leaders themselves have acknowledged that the system remains “optimised for the past, not the needs of the future.”

• Procurement bottlenecks: Frameworks that prioritise cost and assurance over speed, often measured in years instead of months.
• Fragmented architectures: Allies running on siloed platforms that struggle to share intelligence seamlessly, especially in coalition operations.
• Sovereignty concerns: Overreliance on non-sovereign hyperscaler SaaS platforms, which cannot guarantee compliance with national or NATO data handling mandates.
• Operational lag: Mean time to decision is still too often measured in hours or days, when modern threats demand minutes or seconds.

These gaps are not just inefficiencies; they are vulnerabilities. In a contested environment where adversaries adapt quickly and exploit delay, NATO’s strength lies in reducing time-to-action and ensuring resilience under pressure.

Intelligent Interoperability in Practice

The answer lies not simply in connecting systems, but in building intelligent interoperability — architectures that combine speed, sovereignty, and resilience.

• At the tactical edge: Forces must maintain continuity in disconnected, degraded, intermittent, or low-bandwidth (DDIL) environments. Communication platforms and workflows need to function seamlessly, even when satellite links fail or networks are contested.
• Across coalitions: Secure workflows must allow information to flow between NATO members, 5 Eyes allies, and mission partners without compromising classification or chain of custody. Attribute-Based Access Control (ABAC) ensures “together” does not mean “all access.”
• In industry partnerships: Defence and technology providers must move away from rigid, transactional contracts towards open architectures and closer collaboration. As defence leaders have consistently stressed, success requires industry to work alongside warfighters, testing and adapting at wartime pace.
• In innovation ecosystems: Sovereign AI/ML systems can augment human decision-making, but only if their insights are embedded into workflows that reach the right people, at the right time, with the right level of accreditation.

This is intelligent interoperability: not just exchanging data, but enabling trusted, sovereign collaboration that accelerates mission execution across all domains.

Looking Ahead: The New Reality of Multi-Domain Operations in NATO

The real question is what future leaders will say about the choices NATO and its members make today. Will they say that allies embraced the why, answered the how, and delivered the what? Or will they say bureaucracy, silos, and inertia slowed us down while adversaries adapted faster?

“Deter. Fight. Win. Together.” is more than a rallying call from a new CDS. It is a test of whether NATO can modernise its systems, relationships, and architectures at the speed required by today’s threats. Success will not be measured in policy documents or procurement frameworks, but in mean time to action — in how quickly intelligence becomes decision, decision becomes action, and action delivers mission success.

If deterrence is to hold, if fighting is to succeed, and if winning is to endure, NATO must prove it can act — not alone, not slowly, but together.