On Tuesday, in the Downing Street garden, Keir Starmer delivered a grim, generation-defining warning that “things will get worse” for Britain. On Wednesday, in Berlin, he gave a more upbeat resetting of European relations, with more to come in Paris, describing it as a “once in a generation opportunity”. The abrupt juxtaposition is striking. It embodies why so many still find it so hard to get a convincing handle on the prime minister and to have confidence in what he is really about.

Many responses to Starmer’s speeches often seem predetermined, in some cases lazily so, while others contain a nagging descant of truth. That has happened this week too. Starmer’s Labour critics said he was not bold enough – but then, that’s what they always say. The Conservatives – who spent the past decade raising performative politics into almost an art form – also dismissed the speech as performative. The Daily Mail denounced an attack on middle England, as usual. The Tory right alleged Starmer was undermining Brexit, whatever that now means.

All of them are wrong, though they are wrong in different ways and to different degrees. The larger reality is that Tuesday in the Downing Street garden and Wednesday in Berlin fit snugly together. That’s because they are two parts of the same Starmer project. This project was summed up in Tuesday’s speech in a pair of phrases, each already familiar and each often repeated: “do things differently” and “fix the foundations”.

Figuring out Starmer may sometimes seem like trying to solve a Wordle problem. You think you know what some of the letters you need are, but it isn’t immediately obvious how they can be fitted together in a way that makes sense. But the truth is that Starmer is fairly easy to read.

In these first two months, Starmer’s project has revealed itself as ambitious and social democratic. It is a long-term attempt to recast a self-evidently broken, unequal and misfiring Britain as a social democratic nation that Starmer grew up wanting this country to be, but which it never quite was. As such, his project is sharply distinct from both New Labour and from the command-economy labourism of the postwar era. This is why, though it may sometimes seem a throwback to earlier Labour eras, it is actually radically different.

Whether this project is sustainable is a massive but quite separate question. Nobody knows the answer to it. What cannot be doubted is that the economic strategy and the international strategy on show this week represent what Starmer wants to do. They are not what he wants in principle or what he wants in an ideal world – he said as much in the Downing Street garden – but they are undoubtedly what he wants here and now, and at this particular point in the political cycle.

Every prime minister knows that they are strongest in the aftermath of victory. They know that tough, unpopular stuff always has to be done first, before the next election begins to dominate. They know that blaming the previous government is an argument that works. Starmer is no different.

That’s why taxes – some, not all – will clearly rise in the budget and why departmental budgets – again some, not all – will be trimmed, in spite of the inevitable rows. It is why he also gives priority to smoothing the way towards much closer European relationships, even though the Brexiters will shout foul (despite having kept relatively quiet so far).

It is no secret that Starmer has a two-term, 10-year governing project that he wants to see to the end. But perhaps it is less well understood how methodical he is. Starmer was always a methodical lawyer, and he has become a methodical politician. He thinks ahead, better than his opponents, and he is ruthless. Everything he does and says at this extremely early stage in his government’s life is groundwork. So this week’s injunctions to fix the economic foundations and to turn a corner in Europe ought to be seen as two sides of the same coin. With politics resuming after the summer, he is attempting to frame his picture of Britain’s 10-year future.

As the Iraq crisis deepened, advisers told Tony Blair that he did not have to be drawn into George W Bush’s war. “It’s worse than you think,” Blair responded. “I really do believe in this.” This may not be a happy precedent, but Starmer has displayed a similar determination at the heart of his own, very different, project. His social democracy is extremely steely.

Will this ambitious project work? It may. The economy is beginning to hum a little more. If the next election is not until May 2029, he also has time on his side. Time for promised houses to be built, for rivers to get cleaner, for hospital waiting times to be reduced, for wise investments to show returns, for cooperation over migration to show some dividends. And, above all, time for the public to notice.

Yet the success or failure of Starmerism is nevertheless not simply down to delivery. Nor is it just down to tax rates either, though too much of the media still make that mistake. It also depends on the kind of Britain within which the Starmer project evolves.

In the Downing Street garden, Starmer talked about how the riots had exposed a “deeply unhealthy society” and a “societal black hole” in a country “where nothing seems to work any more”. It is a bleak vision of a country disfigured not just by racist riots but by things such as the shocking news that 500 children every day are being referred to England’s mental health services. Starmer’s descriptions may be true, but they also come dangerously close to feeding a self-fulfilling prophecy, especially with the public finances under such pressure and when the sense of threat and hopelessness is leading to considerable personal despair.

In 1940, David Low drew a famous cartoon: All Behind You, Winston. It showed a unified – and all-male – Britain marching determinedly behind its leader to combat the wartime threat to the nation. Though we should not underestimate Starmer’s ambition, or the importance of what he is attempting, or the goodness of the public, it would be naive to expect the peacetime Britain of 2024 to pull together so readily behind its prime minister to overcome its peacetime national troubles.

• Martin Kettle is a Guardian columnist