For Labor in government, it has been days of dislocation and soul-searching. Absorbs a right triumph on the scale of Donald Trump takes time. In the first instances, the British government has naturally turned to the most immediate problems of Ukraine and trade. But they are just the beginning.

Some argue that Labor needs to think hard about the failure of the Kamala Harris campaign. I don’t agree. Labor should not reflect on that at all. The overarching mistake the Democrats made in their campaign – that grinning, self-indulgent, celebrity-invaded carnival of condescension – was the antithesis of Labour’s disciplined, grim, gloomy, always serious summer campaign. That horrified Labor observers sent to the Democratic convention. No: all that matters is looking ahead to the Trump world.

Both on the Russian war and the tariffs, work had already been done by a London administration which expected him to win. David Lammy has been instrumental in courting the Maga Republicans and met with JD Vance repeatedly.

The assumption is that Trump means what he says about tariffs. Much of his appeal to working-class America was his promise to drive up the cost of imports and persuade businesses to “recover.” This is a romantic, nostalgic policy that will also drive up US inflation, but it is central to Trump’s thinking.

So the British strategy, to treat Trump as a transactional leader, not an ideologue who just needs to read a little more Adam Smith, will be based on convincing Trump that he has more to gain than to lose by favoring Britain. Peter Mandelson, again tipped as US ambassador, is already testing the argument on television.

Ukraine is more urgent and even more difficult. Trump’s election is a significant victory for Putin. The idea that in the medium term the US could be replaced by Britain and France – perhaps, as Polish Prime Minister Donald Tusk suggests, in a new three-way pact – as supporters of Kiev is fanciful and dangerous.

Trump was always right about the free-riding instincts of European members of NATO. But it is too late to reopen the debate now. Europe is poorly defended and deeply divided. The collapse of the German government and the arrival of a Le Pen presidency in France do not seem far off. Much of the rest of its leadership is indecisive. Even a fundamental change in defense spending this winter would have no practical effect until long after Kiev’s defeat.

John Healey, the defense secretary, made a good start by signing a new industrial and defense deal with Germany last month. But the official line to delay an announcement about when the UK can reach 2.5 per cent of GDP on defense is quite shameful. A promise – in this case in the election manifesto – without a timetable is no promise at all. Yes, of course, for much of the detail it is right to wait for George Robertson’s Strategic Defense Review. He is shrewd and, as a former defense secretary and former NATO secretary general, very experienced; and yes, everything needs to be looked at again. When Robertson reports in the first half of next year, let’s hope he’s looked over Britain’s missile defences, our expensive, accident-prone carriers and the grossly bloated procurement bureaucracy that is the Ministry of Defense – and takes an Elon Musk-sized scythe to it.

But … but … still … all this will take place alongside a wider departmental spending review (the first since 2021) which will mean the Treasury’s calculations will overshadow the Defense requirements. Time is short. After the Tory years we have a national defense posture comparable to that of the 1930s before rearmament began. Is a patriotic, confident Labor government really not going to do anything big to turn that around? One minister muses: “We’re going to be pushed a lot harder on this now.”

I don’t pretend this is easy. Any hit to our trade from US tariffs, combined with a need to find more money for defence, will take a battering from many of Rachel Reeves’ finance minister’s assumptions. The consequences elsewhere, including for welfare policy, will be serious.

These are the giant waves from the US that are already rippling through British politics. On his trip to Baku, Keir Starmer brutally recast his core policies of economic growth and secure borders – a major retreat from the “Five Missions” that both aligns him more closely with Trump’s agenda and acknowledges a truth reverberating through Whitehall: that Labour’s public service reform agenda barely exists. One consequence is likely to be a dramatic government reshuffle, probably in May.

This is a cultural victory even for the right. Because we share a media space with America, we are vulnerable to the changing climate in Washington on – for example – climate change and the treatment of illegal migration. Farage-ism is reinforced. A senior Starmer ally tells me: “Climate skepticism and mass migration skepticism will become more mainstream simply because they are the views of the most powerful person in the world.”

How will the party, even in the Riksdag, respond? Natural Trump-haters, Labor people will loathe the spectacle of their ministers being polite, even bending the knee, to the great orange king across the water.

Starmer, as a man who believes his first duty is to country and state, will do whatever he thinks needs to be done. It won’t make him more popular.

Trump’s victory also means a subtle tilt in the political balance at the top. Within the government there are effectively three factions: there are the Starmer loyalists such as Rachel Reeves, Nick Thomas-Symonds and Bridget Phillipson. Then there are the Blairites: Wes Streeting, Pat McFadden, Peter Kyle, Liz Kendall. And there is the moderate left, led by Angela Rayner and Ed Miliband, and comprising most of the rest of the cabinet.

All of these groups intersect and merge – McFadden is both Starmerite and Blairite. But because of the need to address Trump’s worldview, the Blairite “realists” are now growing in influence in a way that Starmer had not originally planned.

Jonathan Powell, Blair’s right-hand man throughout his premiership, is back as national security adviser. Liz Lloyd, who first started working for Blair in 1994 when he became opposition leader and stayed on to be deputy chief of staff in his final administration, is back as Starmer’s head of delivery. Mandelson, who friends say is “struggling” between wanting to be chancellor of Oxford University and ambassador to Washington, may yet be back.

Individually, I can easily argue for each of these appointments, strengthening the Starmer operation on points of potential weakness and bringing genuine government experience. But take them together and the result is growing unease among the soft left and more traditional, domestically focused ministers.

Starmer does not like factions or “playing politics”, but he now needs a strategy to avoid divisions. It can only be based on going back to the basics, thinking harder about the impact of interest on family budgets and finding a border policy that brings visible change. He also needs to strengthen the center, and there will be changes, especially on the communication side.

Trump’s triumph is much more than “sound off”. These are the most difficult days yet: ministers are talking privately that this is just a one-man government after all. There is no way to re-election without people feeling better off and calmer about the country’s security. Starmer is right: everything else comes second.

(See also: The Case of Justin Welby)