A big moment and a big decision, ahead of a big meeting.
The government’s announcement that it will crank up defence spending and shrivel the international aid budget amounts to a big shift in strategy, posture and political positioning.
Take a look at the Labour Party’s election manifesto, written less than a year ago, if you would like proof of that.
On page 125, it says: “Labour is committed to restoring development spending at the level of 0.7 per cent of gross national income as soon as fiscal circumstances allow.”
The party is now committing to doing the precise opposite – cutting development spending by the same amount by which it had promised to raise it.
There is nothing like an outspoken American president and an imminent visit to the White House to sharpen the mind – and hey presto, along came this announcement just as the prime minister packs his shirts for his trip across the Atlantic.
Along came the thumbs-up from the Trump administration not long later.
But it is also true that there has been a growing recognition for some time and across several parties that more money had to be spent on defence.
The prime minister has taken to recalling how the Berlin Wall coming down made him feel. “It felt as if we were casting off the shackles of history, a continent united by freedom and democracy,” as he puts it – contrasting that with the reality of Russia’s invasion of Ukraine.
A wider critique along these lines has been crystallising for some time: the sense that the 1990s were a holiday from history, as Jonathan Freedland called it, and that the end of the Cold War had created a peace dividend where defence budgets could atrophy and the money could be spent on hospitals and schools, for instance.
Instead, not only is there war in Europe, there is an occupant of the White House with seemingly little regard for the American security umbrella this continent has relied upon since World War Two.
Little wonder, then, that we have seen a blitz of the jitters in European capitals as presidents and prime ministers try to work out what it may or may not mean.
The task facing Starmer – the second strand of the European tag team of leaders to visit Washington, after President Emmanuel Macron on Monday – is to attempt to mould President Donald Trump’s position.
Over the coming weeks and months, can a deal be done where the war stops, Ukraine does not feel defeated, Europe does not feel imperilled and transatlantic relations are as near to conventional as possible?
It is not going to be easy.
The prime minister’s trip to the White House is but one building block in developing answers to these questions.
And then, over the following weekend, Starmer will host a gathering of European leaders to reflect on where the conversations so far have taken us.
President Volodymyr Zelensky is expected in Washington soon too.
The next few weeks could prove crucial.