The moment that determined the outcome of Labour’s defence review could be judged to be just over three years and three months ago when Russia invaded Ukraine.
And, indeed, the 130-page detailed document will draw heavily on lessons learned from the war currently raging on the edge of Europe.
As the defence secretary John Healey said on Sunday, the government’s response has been designed to send a “message to Moscow”.
But, in reality, the most important moment in the run up to the review happened in January – when Donald Trump entered the White House for the second time.
The US president has consistently pressed Nato allies, of which the UK is one, to increase how much they spend on defence – or else.
In response, Keir Starmer announced a hike to 2.5 per cent of GDP within the next two years. And Mr Healey went further this weekend, saying he had “no doubt” it would reach an ambition of 3 per cent by 2034.
Like all major European leaders, the prime minister knows how much Nato depends on the US, and how much its current leader wants to hear of other countries stepping up.
The review itself has been written jointly by Labour grandee George Robertson, who is himself a former Nato secretary general, as well as Richard Barrons, a retired British army general, and Fiona Hill, a former adviser on Russia to one… Donald Trump.
This strategic defence review will not just send a message to the Kremlin, but to Washington as well.
But will it be enough?
The president has called on Nato countries to spend 5 per cent of GDP on defence. And Lord Ricketts, a former national security adviser, has suggested that ultimately the UK would have to rise to 3.5 per cent of GDP, warning that one of the lessons of Ukraine was the effect of sheer numbers, whether that be in terms of manpower or equipment.
As part of the review, the UK will build up to 12 new nuclear-powered attack submarines, as part of a joint programme with the US and Australia, called Aukus.
Other decisions could see the UK buy US equipment. On Sunday, Mr Healey also appeared to confirm he wanted to buy American-made planes armed with tactical nuclear weapons, in what would be seen as a major expansion of the deterrent intended to counter the growing threat posed by Russia.
The full scale of the government’s response to the review – it is thought to have accepted all 62 of its recommendations – will reset the UK’s defence strategy for the next decade.
Downing Street will be listening out for the response from the Kremlin, and the White House.
