Building the arsenal of trust: India–UK reset the rules of strategic cooperation

The meeting between Prime Minister Narendra Modi and UK Prime Minister Keir Starmer in Mumbai, accompanied by the largest-ever UK CEO and academic delegation, was much more than a ceremonial reprise of bilateral friendship. Instead, it illuminated a pragmatic shift in India–UK relations where defence cooperation has quietly taken centre stage—a critical development in an age of great power competition, mounting security risks in the Indo-Pacific, and the global search for resilient, trusted allies.

For decades, the India–Britain relationship was hemmed in by history and habit. There was strategic comfort but little operational consequence—a partnership rooted in exchange visits, diplomatic overtures, and the soft power of a globally dispersed diaspora.

The Mumbai summit , then, marks a new phase,one where defence diplomacy is not a sideshow to trade, but the very platform on which future prosperity and stability will be built.

The tone was set by reminders of shared democratic values and historical camaraderie, but the substance lay in the contracts.

At the top of the agenda were agreements on defence co-production and technology transfer—areas where India has long sought British willingness to treat it as a co-creator rather than a mere market. The Lightweight Multirole Missile (LMM) deal exemplifies this new approach: a direct government-to-government arrangement that sees India as a trusted customer and prospective collaborator, not simply a buyer. This transactional trust was mirrored in agreements for sharing advances in maritime electric propulsion and establishing protocols for co-designed naval vessels, where British legacy engineering and Indian manufacturing scale can combine for competitive and strategic advantage.

The pivot goes further, for the first time, Indian Air Force instructors will be embedded within the UK’s Royal Air Force, a move signalling true operational integration and trust. On the high seas, joint naval drills—particularly the KONKAN series have developed from signal exercises into meaningful platforms for doctrine exchange, coordination in anti-submarine warfare, and experimentation with multi-domain concepts. The creation of a Regional Maritime Security Centre of Excellence under the Indo-Pacific Oceans Initiative represents not just the pooling of resources, but the recognition that credible deterrence in a region as complex as the Indo-Pacific demands that intelligence, platforms, and personnel flow seamlessly between partners.

This defence realignment sits atop a broader framework of technological and industrial convergence that is rapidly gaining momentum. The UK’s post-Brexit search for strategic partners dovetails with India’s Atmanirbhar Bharat drive, resulting in a mutual willingness to co-invest in R&D, diversify sourcing in critical minerals, and collaborate on next-gen tech such as AI, quantum, semiconductors, secure communications, and green ship propulsion. Here again, the rhetoric at Mumbai was followed up with commitments to make Indian and British industries, universities, and start-ups the beating heart of the new relationship. The setting up of the the India–UK Connectivity and Innovation Centre and the Joint AI Research Centre serves this ambition, creating institutional vehicles for genuine knowledge exchange and technology development with direct defence applications.

These frameworks are not mere abstractions. Both governments understand the necessity of “resilience by design”—ensuring that supply chains for critical platforms and components can withstand geopolitical turbulence, sanctions, or sabotage. The Critical Minerals Industry Guild, with a supply chain observatory anchored at IIT-ISM Dhanbad, is a direct response to this imperative. It ensures security of inputs not just for civilian industry but for the military-industrial ecosystem that will increasingly define both countries’ global leverage.

Maritime security emerged as an unmistakable focus throughout the Mumbai dialogues, reaffirmed by joint condemnation of terrorism, commitments to safeguarding freedom of navigation, and expanded ISR (Intelligence, Surveillance, Reconnaissance) and data-sharing operations across India’s and Britain’s growing naval footprints. In a world where non-state and state actors alike threaten maritime trade, uphold sanctions evasion, or project force through piracy and unmanned systems, the bilateral coupling of India’s Navy with the UK’s Carrier Strike Group is more than symbolic—it makes for a credible deterrence architecture, especially as both countries double down on participation in wider frameworks like the Quad and global task forces.

Beyond the hardware and software, both sides recognized the necessity of investing in human capital —the backbone of sustainable strategic partnership. UK universities opening campuses across India, and new science, engineering, and strategy programs crafted for bilateral flows of officers and students, reflect a deliberate strategy to create a cadre of future-ready military technologists, analysts, and strategic thinkers. The migration and mobility agreements, often seen through the lens of economics or education, must now be considered essential to defence as well: every academic, startup founder, or doctoral student transplanted between Birmingham and Bengaluru seeds the trust and transferable expertise that make defence ties credible and agile.

The Mumbai summit did not neglect the big issues of our time: climate security, pandemic resilience, and counter-terrorism, all areas where “softer” security threats can undermine the very bases of military strength. With joint climate tech funds, offshore wind task forces, and clean energy MoUs in place, both governments are future-proofing strategic assets against next-gen challenges that will almost certainly impact defence postures, from the Arctic to the Arabian Sea.

Policy challenges remain

A partnership of this scale and ambition faces inevitable headwinds: slow procurement cycles, regulatory friction, offset hurdles, and the need to align “Make in India” with “Britain as a Third Country” in global supply chains. The question for policymakers will be whether the momentum generated in Mumbai can be institutionalized into agile monitoring mechanisms, timely review protocols, and robust dispute resolution frameworks. Only then will agreements morph into platforms, and platforms into daily operational readiness.

For all the ceremony and symbolism, the Mumbai meetings signal a partnership in motion, not at rest. India and Britain can no longer afford to treat defence merely as a pillar among others—the volatility of the Indo-Pacific, the shadow of global terror, and the race for technological dominance make it the lodestar. If Delhi and London manage to turn ambition into readiness, trust into capability, the next decade will see them not just keeping pace with global transformations, but shaping their very contours. In a world where alliances are as important as arsenals, India–UK defence synergy stands out as both model and mandate for purposeful, adaptive cooperation.

Gaurav Kumar is a Researcher at the Centre for Professional Military Studies, United Service Institution of India, New Delhi. He Tweets @gaurav15_isk. Views expressed in the above piece are personal and solely those of the author. They do not necessarily reflect Firstpost’s views.