Keir Starmer’s embrace of defence-first and nuclear future is the key development in British politics since Brexit. There can be little doubt the choice is not a choice at all. It is a decision forced on the British government by the world's changing situation.
The truism that everything has changed for Europe could not be more on-point. The post-Cold War peace dividend has been exposed as an exercise in delusion.
How quickly the defence establishment must now embrace an entirely different way of framing the security challenges a country like the UK must master.
For a start, it is not a matter of preparing for attack but one of being ready for full-scale confrontation. This kind of readiness is both a state of mind for officialdom and a shared enterprise across society.

Nowhere is this more evident than in the expansion of the nuclear arsenal following the Labour government’s Strategic Defence Review, released on Monday. Still under a year since the UK voted for Prime Minister Keir Starmer, it is remarkable how far he has travelled to fulfil his pledge to the “first duty” of any government as defence.
The composition of the panel that led the Strategic Defence Review was a clue to how deep its task would run. It included Lord Robertson, an ex-Nato Secretary General; Fiona Hill, a British-born former American national security lead on Russia and retired general Richard Barrons. They wrote on Monday about how Britain faces a world dominated by state-level confrontation while it is shaken by population growth, climate change, nuclear proliferation and the digital age.
Appointed last year, the three leaders have had to make several course corrections, not least around the policies coming out of US President Donald Trump's administration. What they applauded in their article was that the committed by the UK to go from 2.5 per cent to three per cent GDP spending on defence would create the resources to fund the change they were suggesting.
Donald Trump’s election has had a trigger effect all across Europe. The new German Chancellor, Friedrich Merz, has straight up called for Germany to spend 5 per cent of its GDP on defence.
As experts long concluded, well before Trump, that US strategy was all about China, now Europe’s strategy is all about Russia. America’s pullback is only one part of the picture, now that it is inevitable.
As ever, when a rivalry is a two-sided street an element of synthesis emerges. Russia has found itself with a war economy that is much more dynamic than western economists predicted. The Labour government in the UK is selling its defence plans as a form of reindustrialisation. Germany’s Vorsprung durch Technik (Progress through Technology) economy has struggled to produce real growth for most of this decade. Mr Trump, too, talks of revitalising his country’s industrial base, saying a nation must be built on steel. Three years into the Ukraine war all these blocs are in a symbiotic place, moving in a similar direction but not united on the overall ambitions of their policies.
Ugly truths that cannot be avoided are what’s at play as the scramble for arms plays out.
The question of how good the growth from defence spending will be is a hard one to get right. For sure, it means the states must set the market. About three years ago, I was at a conference where one of the sponsors from a large US defence firm stated his company was only going to build a single extra production line when a client (read government) committed £100 million ($135.4 million) in orders for its output.
By retooling the Russian industrial base for war Mr Putin has created certain internal dynamics that have boosted his position. The reality of a war economy with working-age men pushed to the frontlines gives the Kremlin a lot of internal sway. The very generous death payments for soldiers are recycled as spending power in some of the most worn down parts of Russia.

At the same time, the returns are next to nothing on the battlefield. Ukraine’s resourceful playbook grows ever more audacious as evidenced by Sunday’s reported drone attacks on the strategic bomber fleet. With the UK rushing to upgrade its nuclear position, a blow like that suffered by sabotage is a strategic reverse for Russia.
The sustainable position that Kremlin hopes for is growing increasingly dependent on the talks and resolution offered by Mr Trump. Leave that too late and Russia will truly be left with only the laws of diminishing returns to keep going.
Whatever Russia’s direction, the need identified in the SDR is now for the Europeans to adopt a “modernised Nato First approach”. There are vast sums now being committed by London and officials hope that economic growth will be boosted by the programme of investments.
Despite this the SDR reminds Mr Starmer that an overhaul of Nato is the only effective, affordable option for the UK. That is coded language for America moving out and the Europeans taking their own theatre of security much more seriously than before.