PROFILE: How Ukraine Rewrote the United Kingdom's Military Doctrine

A departing prime minister, a plan that endures

On June 30, 2026, just days before leaving Downing Street, British Prime Minister Keir Starmer signed what may prove his most enduring legacy: the Defence Investment Plan, a commitment of £298 billion sterling — approximately $400 billion — over four years to transform the British armed forces from the ground up. This is not a doctrine update. It is a break.

The architecture of this overhaul rests on a brutal conviction that the war in Ukraine has forced upon all of Western Europe: expensive large platforms, gleaming destroyers, rigid hierarchies — all of that belongs to a world that no longer exists. What the Ukrainian battlefield has taught is the supremacy of the cheap drone, the innovation cycle measured in weeks, the saturation of numbers.

A role reversal that says everything

Tim Willasey-Wilsey, senior associate fellow at the think tank RUSI, put it with disarming clarity: "It is slightly ironic that Britain started training the Ukrainians in 2022, and now it's them who could be training us — they are showing us how warfare needs to be conducted today." That sentence deserves to be read again. Twice. Slowly.

In 2022, the British program Operation Interflex had trained tens of thousands of Ukrainian soldiers on English soil. Four years later, it is the Ukrainian army that provides the doctrinal model the United Kingdom seeks to emulate. The student has surpassed the teacher. And the teacher had the intelligence to acknowledge it.

There is something remarkable in this institutional humility. Great military powers rarely admit that their lessons come from an army that did not exist in its current form five years ago. The United Kingdom, by explicitly embedding Ukrainian tactics in its defence plan, is not simply modernizing its arsenal — it is acknowledging that Ukraine has reinvented the art of war before our eyes.

£298 billion: an envelope that commands respect

The Defence Investment Plan allocates a total of £298 billion over four years. In detail: £15 billion (approximately $19.8 billion) constitutes the immediate boost to modernize the British armed forces. The annual objective: bring defence spending to nearly £80 billion (or $106 billion) by 2029, up from £54 billion today. A jump of nearly 50% in less than five years.

Funding comes primarily from budget reallocations: £10.3 billion identified immediately, the rest to be confirmed in the 2026 Budget. The transport and energy departments absorb the heaviest cuts, respectively £800 million and £2 billion more over four years. Starmer warned his successor not to borrow further to fund defence. The message is clear: security is paid for today, not tomorrow.

The sectoral breakdown: where the money goes

The distribution is telling. More than £63 billion goes to nuclear deterrence — Dreadnought submarines, the SSN-AUKUS programme, a new nuclear warhead, 12 F-35A fighter jets. Some £11 billion serves to strengthen ammunition stocks and the production of long-range weapons and cruise missiles. More than £8 billion funds the sixth-generation combat aircraft programme GCAP (Global Combat Air Programme), developed jointly with Italy and Japan. And £2 billion is allocated to an AI-driven digital combat management system.

These figures compose the portrait of an army that wants to remain in the technological race while absorbing the raw lessons of the Ukrainian battlefield. Nuclear deterrence remains the foundation; digital transformation is its visible future.

One could object that £63 billion for nuclear versus £5 billion for drones reveals a priority still anchored in the Cold War. That would be reductive. Nuclear deterrence responds to a structural existential threat; drones respond to the war currently underway. Both are necessary. What is new is that the United Kingdom has finally accepted funding them simultaneously.

£5 billion to rewrite the rules of aerial combat

The plan's centrepiece, doctrinally, is the allocation of more than £5 billion ($6.6 billion) to the transformation of drone capabilities in the British forces. Of this envelope, £650 million ($860 million) serves specifically for the purchase of cheap aerial and ground drones. The Ministry of Defence has established a drone testing centre it describes as the largest in Europe, and a new task force is charged with scaling up drone production for British forces.

The reference figure cited in all official documents is striking: Ukraine uses 200,000 drones per month. Not per year. Per month. That is the standard against which the United Kingdom seeks to measure itself, or at least not to fall too far short of. Ross Exley, vice president of defence strategy at Hadean — a British technology company sitting on the Defence Industrial Joint Council — said it plainly: "The clear lesson from Ukraine tells us that drones have changed the character of warfare."

Common Combat Vessels to replace destroyers

One of the plan's most powerful signals is what it does not fund. Up to eight Type 83 guided-missile destroyers and Type 32 frigates will receive no new funding. The expansion of the Royal Navy's surface fleet, planned for the 2030s, is abandoned. In their place: at least six Common Combat Vessels — control ships for unmanned systems — accompanied by a whole family of autonomous platforms: Type 93 anti-submarine submarines, Type 91 unmanned missile platforms, Type 92 and Type 94 unmanned aerial and maritime sensors.

The Ministry of Defence summarizes the new doctrine in one sentence: "cheap systems destroying high-value targets, and innovation cycles measured in weeks, not years." This is not merely a formula. It is an admission that war has changed in nature.

Abandoning the Type 83 destroyers is not a trivial decision in a country where naval power is a national identity. Since Trafalgar, the Royal Navy has been a symbol of British greatness. This decision says that Britain has chosen effectiveness over symbolism. It is courageous. It may also be inevitable.

From student to teacher in four years

The trajectory is extraordinary. In 2022, when Ukrainian soldiers arrived at British bases to follow Operation Interflex, nobody imagined that their country, at war for its survival, would become the doctrinal laboratory of Western armies. Four years of total war have produced operational expertise that military academies cannot teach: the speed of adaptation, resilience under maximum pressure, the tactical integration of drones at every level of command.

The British plan explicitly incorporates these "lessons learned from Ukraine." This is not a footnote. It is a strategic orientation. Keir Starmer himself underlined that "Russia's full-scale invasion of Ukraine has fundamentally redefined modern warfare." That phrase in the mouth of a British prime minister represents an epistemological break with twenty years of doctrine dominated by counter-insurgency operations in Iraq and Afghanistan.

The cheap-system-against-expensive-target doctrine

What Ukraine has demonstrated is the fundamental economic asymmetry of the war drone: a $500 device can neutralize a $5 million tank. A drone swarm costing $50,000 can saturate a $300 million anti-missile defence system. Russia learned this lesson at its cost — or more precisely, it attempted to apply it in reverse by flooding Ukraine with Iranian Shaheds. Ukraine understood it and perfected it, developing long-range drones capable of striking refineries 1,500 kilometres away.

The United Kingdom wants to integrate this logic into its permanent doctrine. Defence Secretary Dan Jarvis put it this way: "By choosing to embrace new technologies, I am equipping our forces with the autonomous systems that will give them the advantage." The advantage is no longer in the size of the platform. It lies in the intelligence of its use.

There is a paradox at the heart of this doctrine: the countries with the most to learn from Ukraine are those that, like the United Kingdom, have the budgets to do so. Armies without resources remain trapped in outdated doctrines. Ukraine broke that cycle by innovating under maximum constraint. It remains to be seen whether institutionally comfortable armies can truly reproduce that agility.

A Defence Secretary who slams the door

The birth of the Defence Investment Plan was not without political pain. Former Defence Secretary John Healey resigned over a disagreement on the allocation of defence resources. His departure illustrates the internal tensions of a Labour government that long resisted the idea of substantially increasing military spending, then was forced to pivot as Europe rearmed at accelerated speed.

The Institute for Fiscal Studies (IFS) was direct in its analysis: to reach the 3.5% of GDP that NATO is asking its members to achieve by 2035, the government will need to increase defence spending by the equivalent of £25 billion per year in current value. The current plan only brings spending to 2.7% of GDP by 2030. The gap with the target remains substantial.

A successor awaited with unanswered questions

Irony of timing: it is Keir Starmer who signs the plan, but it is Andy Burnham, expected as successor at the head of the British government in the coming weeks, who will have to ensure its execution. The plan was designed to outlive its author — that is precisely its strength and its fragility. Its strength, because it commits decades of industrial and acquisition policy. Its fragility, because every government tends to reinterpret inheritances to its own measure.

The Ministry of Defence itself acknowledges the absence of a clear roadmap to reach 3.5% of GDP. That is not nothing. But in a context where Germany, France and Poland already exceed proportional British spending, the status quo was no longer tenable.

Healey's resignation is a signal that some within the government itself found the plan insufficient. The real debate is not between those who want to spend and those who do not — it is between those who understand that 2.7% of GDP is not the same thing as 3.5%, and those who think the announcement equals the commitment. The history of British defence is littered with such generous announcements followed by silent cuts.

Forces and capabilities in transformation

Concretely, the British army of 2029 targeted by the plan will be a hybrid force: confirmed nuclear power with its Dreadnought submarines and its new nuclear warhead programme; rising air power with its F-35A fighters and the future GCAP; naval power reshaped around autonomous systems rather than large crewed hulls. The army, for its part, will receive unmanned ground platforms — an acknowledgment that infantry warfare itself is mutating.

The National Collaborative Combat Air programme plans to develop autonomous jets flying alongside piloted aircraft — what is called the loyal wingman doctrine. AI will be integrated at the heart of the combat management system, not as an auxiliary tool but as a structural component of the decision chain. This is no longer an army modernizing itself. It is an army changing its paradigm.

The deficits that remain

But sobriety is in order. The United Kingdom starts from a low base: its defence spending was at 2.2% of GDP in 2023–2024. It lags behind Germany, France and Poland proportionally. Its army has been reduced to its lowest levels in decades. Ammunition stocks were deemed insufficient in the previous year's Strategic Defence Review, which concluded that "state conflict has returned to Europe."

The objective of 2.7% of GDP by 2030, then 3.5% by 2035, is ambitious but remains below what Poland (over 4%) and the Baltic states already do. The United Kingdom is catching up, not leading the way.

I have no illusions about what a four-year plan represents in a country whose electoral cycle is five years. But I take note of this: for the first time since the end of the Cold War, a British government looked at the reality of a war in Europe and said "we are the ones who must change." That is not nothing. It is actually quite a lot.

A security legacy in the shadow of his departure

Keir Starmer leaves power in a paradoxical situation: he announces one of the greatest reinvestments in defence in the United Kingdom's recent history, but will not be there to see the results. His successor Andy Burnham — former Mayor of Manchester, figure of the Labour left — will inherit a plan that constrains public finances for years. That is not the kind of political gift that is always welcomed with enthusiasm.

The portrait of Starmer through this plan is that of a man who chose to make difficult decisions knowing he would not see their political fruits. He raided the transport and energy budgets — flagship sectors for Labour voters — to fund drones and submarines. He resisted pressure from those who wanted to borrow more. This is not the portrait of a coward.

The NATO pressure and the Ankara context

This plan is inseparable from the NATO summit in Ankara and the American pressure on European allies to carry their share of the defensive burden. The promise of €70 billion in aid to Ukraine formulated at Ankara would not have been credible without concrete national commitments. The British Defence Investment Plan is, among other things, a response to that pressure — and a demonstration that Europe can take care of itself without waiting for every arbitration from Washington.

The direction toward a more European NATO — explicitly formulated by Starmer — is a strong political signal in a context where the Trump administration blows hot and cold on its Atlantic commitments. The United Kingdom tells its partners: we are here, we are investing, we are taking our responsibilities. That is a message Europe needs to hear more of.

There is a deeply European subtext in this decision that Starmer — long perceived as lukewarm on major breaks — fully owns. Strengthening the European NATO is also a way of responding to Trump without directly defying him. It is precision diplomacy disguised as defence policy.

From destroyers to autonomous systems

The Royal Navy is perhaps the institution undergoing the most symbolically weighty transformation. For centuries, its power expressed itself in its great hulls: battleships, then aircraft carriers, then destroyers and frigates. The plan's decision to forgo funding new Type 83s and Type 32s marks the end of an era. In their place: control vessels that do not yet exist, designed to coordinate swarms of unmanned platforms.

It is a bet on the future that carries its own risks. Naval autonomous platforms are still in their technological adolescence. The Type 91, Type 92, Type 93 and Type 94 are concepts more than operational realities. But the calculation is made: investing in crewed destroyers whose utility diminishes in the face of hypersonic missiles means buying obsolescence.

The legacy of Trafalgar facing tomorrow's world

Researcher Tim Willasey-Wilsey of RUSI acknowledged that Britain needs a large navy, but that it must become "much lighter and more formidable." That is an elegant formula for describing an industrial and doctrinal revolution. A smaller, more mobile, more intelligent navy — less expensive to operate and harder to neutralize because it is distributed.

Ukraine did exactly that with its navy: its naval forces, decimated after the loss of the cruiser Moskva, managed to push the Russian fleet out of the Black Sea with naval drones and missiles. Without aircraft carriers. Without destroyers. With ingenuity and precision. The Royal Navy looks at that model and sees its future.

The Royal Navy sank the Belgrano in 1982 with a nuclear submarine. Ukraine sank Russian warships with $20,000 drones. Those two facts say everything about the evolution of naval warfare over forty years. The Royal Navy is right to want to belong to the second world rather than the first.

A strong diplomatic signal

For Kyiv, the British Defence Investment Plan is far more than a national rearmament. It is a strategic validation at the highest institutional level. That a historic military power fundamentally restructures its army while explicitly citing Ukrainian tactics as the model — that says something about the nature of what Ukraine has accomplished since 2022.

This signal fits into a context where the United Kingdom remains one of Ukraine's most consistent military supporters. British participation in training initiatives, the supply of Storm Shadow missiles and other advanced weapons systems, and now this rearmament plan inspired by Ukrainian experience compose a coherent picture: London believes that Kyiv is fighting for shared values, and acts accordingly.

Industrial cooperation in perspective

The plan also opens up prospects for industrial cooperation between the United Kingdom and Ukraine. The new drone production capabilities, the testing centres, the rapid innovation cycles — all of this can feed a concrete technological partnership. Ukraine, with its defence industry in full reorganization, needs allies who understand what it is doing. The United Kingdom, with its plan, signals that it wants to be that ally.

Prime Minister Starmer had visited Kyiv earlier in his term to reaffirm British support. His successor Burnham will inherit a relationship that, for once, is structured around mutual admiration and shared lessons — not merely a donor-recipient dynamic.

This partnership will only function fully if the United Kingdom does not forget, in five years, that it was Ukraine who taught it. Institutional collaborations tend to erase the origins of their own ideas. The honesty of today's explicit doctrinal citation must transform into concrete reciprocity tomorrow.

An alliance under constructive tension

The British plan fits into a context of an NATO deeply transformed by the pressures of the Trump administration. American demands to bring spending to 5% of GDP — repeatedly voiced by Washington — have had a paradoxically positive effect: they forced countries like the United Kingdom, Germany and France to make decisions that their pre-war budgetary comfort had postponed indefinitely.

Trump is a necessary evil for the West: his brutal transactionalism achieved what two decades of soft diplomacy had not — convincing Europeans that their security cannot be subcontracted to Washington. The British Defence Investment Plan is a response to this reality, even if its authors would never frame it in those terms.

Europe as a credible security actor

Starmer's formula about a "more European NATO" is the political keystone of the plan. It says that the United Kingdom — despite Brexit, despite the ambiguities about its place in the European security architecture — chooses to strengthen the European pillar of NATO. This decision has implications that go beyond national rearmament alone: it encourages European partners to do the same, and it signals to Moscow that Europe is not falling apart.

Putin's Russia bet that the war of attrition in Ukraine would exhaust Western support. This plan says the bet is lost. Europe is rearming, drawing lessons, changing its doctrine. And it is doing so by looking to Kyiv as its teacher.

I am not naive about the timelines: 2029, 2035, promises subject to budgetary conditions — history is full of defence plans that melted on contact with fiscal reality. But the direction is right. And in current geopolitics, direction matters as much as speed.

Production capacity as the critical variable

The reference to Ukraine's 200,000 drones per month raises a fundamental practical question: can the United Kingdom realistically reach that level of industrial production? The honest answer is: not in the immediate term. Mass production of low-cost drones requires a specific industrial chain — large quantities of electronic components, battery suppliers, rapid assemblers, software integration teams. That is an industry built over years, not months.

The task force created by the British plan is charged with continuously "scaling up drone production." That is the formulation of a problem more than a solution. Experts at Hadean and RUSI know that closing the gap with Ukraine — which produces its drones under wartime pressure, with an industry reorganized around that single priority — will take several years even with the best political will.

The innovation cycle as a cultural challenge

The real challenge is not only industrial. It is cultural. The Ministry of Defence talks of "innovation cycles measured in weeks, not years." But British military acquisition processes — as in all large countries — operate according to contractualization and validation logics measured in years, even decades. The JSF F-35 took more than twenty years to become operational. The Type 45s accumulated delays and cost overruns.

Shifting to a cycle of weeks requires bypassing these processes, creating accelerated acquisition pathways, tolerating higher prototype failure rates. That is what Ukraine did under survival pressure. The United Kingdom will have to find how to reproduce that agility in a peacetime context — which is, historically, much more difficult.

This is the deep paradox of every attempt to import the lessons of a war without being in it. Ukraine innovates fast because it has no choice. The United Kingdom may innovate more slowly because it has a choice. The only antidote to that comfort is to understand — deeply, not merely intellectually — that the Russian threat will not disappear with the end of the Ukrainian conflict.

Supporters and sceptics

The resignation of John Healey suggests the Labour government did not debate these questions in unanimity. There is, within the Labour Party, a traditional current more reluctant to large military expenditures, more wary of the defence industry, more inclined to see diplomacy and development as alternatives to armaments. That current has not disappeared with the Defence Investment Plan. It has simply bowed to a geopolitical reality it can no longer deny.

The question that will remain open is that of the long term: will a Burnham government, or a Labour government under other leadership, maintain the course toward 3.5% of GDP by 2035? Elections pass, priorities change, economic crises rearrange budgets. The plan's robustness depends as much on lasting political conviction as on budget writing.

The Conservative opposition and its positioning

On the Conservative side, the plan was received with predictable ambivalence: it is difficult to criticize an increase in defence spending when you presided over its insufficiency for more than a decade. The Conservatives instead questioned the sources of funding — notably the cuts to transport and energy — and the feasibility of the industrial targets. That is a legitimate criticism, but it lacks the moral weight necessary to constitute a genuine alternative.

The reality is that on defence, the British national consensus has shifted. The United Kingdom is spending more, reforming more, and now accepts that its model of warfare must change. The question is no longer whether, but how — and at what speed.

There is something historically remarkable about the fact that it is a Labour government that carries this plan. The British left has a long tradition of wariness toward the military-industrial complex. That it is Starmer — and not a hawkish Tory — who signs this document is proof that the reality of the Russian threat has crossed partisan lines.

When defence competes with social spending

Funding the plan through budget reallocation — cuts to transport (£800 million), energy (£2 billion), and a general 1% capital cut across all departments — creates real tensions with other government priorities. The National Health Service (NHS), infrastructure, energy transition policies — all of this is affected, even marginally, by the reallocations decided upon.

Starmer himself warned his successor not to borrow more to fund defence. This choice not to resort to debt is politically courageous — and economically reasonable in a context of still-elevated interest rates — but it places the government in a position where every pound for defence is a pound less for something else. That trade-off will be the political terrain of the coming years.

The IFS and the structural funding gap

The Institute for Fiscal Studies has calculated that reaching 3.5% of GDP by 2035 requires £25 billion more per year in current value. The current plan commits approximately £15 billion over four years, or less than £4 billion per year. The gap is £21 billion per year. That is considerable. It means the current plan is a first step, not a complete solution.

The next two budgets will need to confirm the trajectory. The 2026 Budget, expected in the autumn, will need to confirm the £4.7 billion still unallocated. If that budget confirms the commitment, the plan gains credibility. If it dilutes it, the political fragility of the promise will be exposed.

£25 billion per year missing to reach the NATO target: that IFS figure should not pass through press releases without being questioned. It says that the current plan is courageous but insufficient. That is not a criticism of its author — it is a warning for his successors. Geopolitical reality will not wait for the next electoral cycle to manifest itself.

The trilateral programme with Italy and Japan

Among the plan's most structural investments stands more than £8 billion for the Global Combat Air Programme (GCAP), the sixth-generation fighter developed jointly by the United Kingdom, Italy and Japan. This programme is one of the most ambitious in the history of combat aviation — and one of the most revealing of the new geographies of Western alliance.

The choice of Japan as partner — in a programme that links a NATO member state to an Indo-Pacific partner — says something about the growing convergence of Atlantic and Pacific security architectures. China, North Korea, Russia: these three actors constitute a threat to both Europe and the Indo-Pacific. GCAP is, among other things, a response to this triangulation of risks.

AI at the heart of the combat system

The £2 billion for an AI-driven digital combat management system may be the plan's most silent and most structural investment. The war in Ukraine has shown the importance of information processing speed in tactical decision-making: identifying a target, validating a strike, coordinating multiple platforms — all of this now happens in seconds, not minutes. AI is no longer an auxiliary tool; it is at the heart of the command chain.

But this integration raises unresolved ethical and operational questions: how far should lethal decision-making be delegated to an algorithm? How can the robustness of systems against cyberattacks and adversarial electronic countermeasures be guaranteed? The plan invests in the technology without yet providing a public answer to these questions — which is both normal for an acquisition plan and concerning for a democracy that must be accountable to its citizens.

AI in combat decision-making is the real unspoken subject of this plan. We talk of drones, submarines, frigates — but the deep issue is knowing who decides when an algorithm is in the loop. This debate is not yet public in the United Kingdom. It should be.

What a defence plan reveals about an era

The British Defence Investment Plan of June 30, 2026 is a public policy document. But read carefully, it is also an admission of the times: collective security can no longer be subcontracted, war has returned to Europe in a form that military academies did not anticipate, and Ukraine — a country many thought doomed to capitulation in 2022 — survived, fought, and transformed the military doctrines of the world's oldest armies.

This plan is the portrait of a nation looking history in the face. With delay, with shortcomings, with political and budgetary compromises that reduce its scope. But looking. That is not nothing. At a time when populist governments in central Europe seek to evade collective defence obligations, the British choice to go in the opposite direction has a value that transcends the numbers.

Ukraine as a mirror of the West

Ukraine did not ask to be the laboratory of modern warfare. It became so under the pressure of a criminal invasion. That its sacrifices serve to reform Western armies is, at bottom, the most positive transformation that could emerge from this tragedy. It is not a consolation for those who have lost loved ones. But it is a form of meaning that nations need to carry them through wars.

In the end, what this plan says most importantly is not how much the United Kingdom will spend. It is what it implicitly acknowledges: that its own army has lessons to learn from a country that has been fighting for its survival for more than four years. That acknowledgment is rare in military history. It says that the West, when honest with itself, knows that Ukrainian resistance is not merely admirable — it is instructive. And that the instruction deserves to be repaid, not only in armaments, but in doctrinal humility.

Keir Starmer departs. The plan remains. Ukraine keeps fighting. And the United Kingdom — for the first time since the Falklands War perhaps — looks at itself in a military mirror and decides to change what it sees.

By Maxime Marquette, columnist

Editorial stance

I am not a journalist but a columnist and analyst. My expertise lies in observing and analysing the geopolitical, economic and strategic dynamics that shape our world. My work is to take political strategies apart, to understand global economic movements, to put the decisions of international actors in context and to offer analytical perspectives on the changes that are redefining our societies.

I do not claim the cold objectivity of traditional journalism, which stops at reporting facts. I claim analytical clarity, rigorous interpretation and a deep understanding of the complex issues that concern us all. My role is to give meaning to the facts, to place them in their historical and strategic context, and to offer a critical reading of events.

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Nature of the analysis

The analyses, interpretations and perspectives in the analytical sections of this article are a critical, contextual synthesis based on the information available, the trends observed and the expert comments cited in the sources consulted.

My role is to interpret these facts, to set them in the context of today's geopolitical and economic dynamics, and to give them a coherent meaning within the larger story of the changes shaping our time. These analyses reflect expertise built through continuous observation of international affairs and an understanding of the strategic mechanisms that drive global actors.

This article describes a documented state of affairs on its publication date, not a prediction: later developments may shift its outlook. No update is promised in advance; when an article is corrected or completed, the change is dated in the text.