While Britain's defence strategy comes under fire, the nuclear arms race continues

When British Defence Secretary John Healey resigned on Thursday night, Australian time, the implications of his move were largely judged by what it would mean for the future of his embattled Prime Minister, Sir Keir Starmer.

Healey was followed out the door hours later by the armed forces minister, Al Carns, and two ministerial aides.

The future shape of the British government is, of course, of great interest. And political battles are always a subject of public fascination.

But, in an increasingly rare event these days, Healey's resignation was on a matter of principle.

That matter of principle helps shine a light on a much bigger story about the state of the world, geopolitics and war preparedness than the implications of resignations at Whitehall.

"You have been unable, and the Treasury has been unwilling, to commit the resources that the nation needs to defend the country at this time of rising threats," Healey wrote, damning his leader for failing to provide what many people would regard as the most fundamental of protections for a country's population: its defence.

Britain's growing nuclear weapon spend

There has been a long and complicated brawl going on in the British Labour government about defence spending; much of its public face being about the fact that other parts of the government would have to cut spending to fund plans to significantly increase defence spending — by about 15 billion pounds.

The debate has dragged on for some time since a strategic review of Britain's defence needs was completed last year.

As the Royal United Services Institute wrote, the review never really gave a full description of the size and shape of the armed forces that was envisaged "akin to the kind of 'order of battle' seen in previous defence reviews".

In other words, while the overall size of the British defence budget has been fought over, there is little known about how exactly it will be spent. Questions linger — does the UK aim to have a land army to fight a war in Europe? (Answer: unlikely). Does it need more conventional missiles and drones for such a war? And what's the role of manned and unmanned naval power?

But one capability that seems to just blunder on with little scrutiny and increasingly little strategy is Britain's nuclear capacity.

Two reports released this week document a surge in the number of nuclear weapons around the world in the past year. And not just their growth in number but a seemingly growing reliance on them, in an environment where most of the deterrence and detente architecture which kept things manageable in the past has been eroded.

The nature of nuclear weapons is changing. Analysts say the gap between conventional weapons and nuclear weapons is getting smaller, and the way nuclear weapons are conceived to be used is changing.

What makes the UK's role in this story so compelling is that the current fracas has highlighted the fact that nuclear weapons will soon represent 25 per cent of Britain's defence spend.

Not only that, but the small island nation has overtaken Russia in the past year as the third biggest spender on nuclear weapons.

The Stockholm International Peace Research Institute (SIPRI), which tracks military spending, noted the UK also announced last year its intention to buy 12 nuclear-capable F-35A combat aircraft from the USA, and equip them with US nuclear bombs, in order to join NATO's nuclear sharing arrangements. The plan walks back the decision from the 1990s to denuclearise the Royal Air Force.

'A worrying development'

The rationale for escalation in nuclear weaponry is strongly linked to the United States' declared plan to reduce its commitment to European defence.

So it is hardly surprising that the UK might be seeking to compensate for this.

But as British defence analyst Carne Ross said this week "the other unnoticed thing that's going on in the UK and indeed Europe as a whole, is that the US is increasing its deployment of tactical nuclear weapons, so-called tactical nuclear weapons, which can have a yield of 50 kilotons, which is three times greater than the bomb used in Hiroshima".

"There appears to be a rapid increase in the deployment of these tactical weapons in Britain, but also on continental Europe, maybe Turkey and elsewhere — bizarrely in response to the fact that Trump is less committed to the conventional military defence of Europe," he told Al Jazeera podcast The Inside Story.

"This appears to be an appeal from the Europeans for greater security through tactical nuclear deployments. This is a very bizarre and paradoxical and indeed worrying development."

But more than the usual difficulty in knowing just how defence dollars are being spent, anything specifically related to nuclear weapons has a tradition of being particularly opaque.

The Financial Times reported last week that Westminster's Public Accounts Committee found that the Ministry of Defence has "not provided 'sufficient transparency' over its ever-increasing spending on nuclear weapons, which accounts for roughly a fifth of the UK defence budget".

"The report criticised the secrecy surrounding Britain's nuclear spending, saying the Defence Nuclear Enterprise, a collection of organisations that operate and maintain the UK's nuclear deterrent, 'lacked accounting records to support more than £6bn of its assets' in its 2024–25 annual report," the FT reported. 

Britain's nuclear deterrent consists of submarines carrying US-made Trident nuclear missiles. Creating a new class of four Dreadnought nuclear submarines to take the place of the ageing Vanguard-class subs is expected to cost £41bn.

Nine nuclear-armed countries spending more

Where the story of the UK's nuclear spend goes even wider though is in another report released this week by the anti-proliferation group the International Campaign to Abolish Nuclear Weapons (ICAN) which documents the last year's spending on nuclear weapons by the nine nuclear-armed countries. (That's the US, China, UK, Russia, France, India, Pakistan, Israel and North Korea.) 

ICAN says those nine states spent just under US$119 billion ($168 billion) on their nuclear arsenals in 2025, a staggering increase of 19 per cent from the previous year.

The US had the biggest increase (US$12.4 billion) and spent more than all the others combined — US$69.2 billion.

China remained in second place. But the UK came in third at US$12.6 billion, overtaking Russia.

While the US and Israel went to war to stop Iran getting nuclear weapons, they are both believed to have them — even though Israel has never confirmed it possesses them.

ICAN's Susi Snyder told the same Al Jazeera podcast this week: "On average, we see an increase of about 10 per cent. Last year, it was almost double that. So it is by far one of the largest increases we have ever seen."

Nuclear war and weapons have historically been seen as a threat of missiles exchange over continents in a showdown between the "great" powers.

But the sheer cost and difficulties of warfare in modern times gives too many countries some sense of relatively easy security in having a nuclear "deterrent".

SIPRI notes that in 2025 several European states, including Germany, indicated a desire to supplement NATO nuclear-sharing arrangements focused on US weapons with similar arrangements with France and the UK.

A changing warfare landscape

There are two major confrontations going on in Europe and the Middle East at present. (The conflicts in Africa seem beyond the reach of nuclear stand-offs at present).

In both the war in Ukraine and the war in the Middle East, we have been witnessing increasing signs of frustrated eruptions between combatants — notably around the Strait of Hormuz this week — as fights bog down into apparently intractable conflict.

The risks of an accident have seemed all too clear.

The prospect of nuclear weapons being used in either Ukraine or the Middle East, rather than being fired between Moscow, Washington or Beijing has risen.

SIPRI Director Karim Haggag says that "influential voices, including some world leaders, are advocating nuclear weapons as a guarantee against attack by a hostile state. But making national defence and security strategies dependent, or more dependent, on nuclear weapons could significantly increase nuclear risks."

Tariq Rauf, the former head of verification and security at the International International Atomic Energy Agency agrees.

"First of all, we have new types of delivery systems, supersonic delivery systems, hypersonic delivery systems," Rauf told Al Jazeera. 

"The gap between large conventional weapons and small-yield nuclear weapons is now largely disappearing. So, we can now have conventional weapons used with strategic effect to even try to take out nuclear bases and decision makers."

The Healey resignation came just hours before he was supposed to stand up at Portsmouth to trumpet AUKUS with Australia's Deputy Prime Minister and Defence Minister Richard Marles, and Foreign Minister Penny Wong.

Like much of the British media, Marles chose to focus on the personnel change, rather than what might have driven it, in his comments.

AUKUS, he said, would continue, as it already had across changes of government in the UK, the US and Australia "because it fundamentally is in the national strategic interests of the United Kingdom, the United States and Australia, and all of that gives us a sense of confidence that we will be able to deliver this".

The only question is over the value of delivering "this" at a time when the threats and means of warfare are changing by the day, in ways most of us can't easily see.

Laura Tingle is the ABC's Global Affairs Editor.