On a visit on Thursday to the shipyard at Barrow-in-Furness, where the next generation of Dreadnought-class nuclear-armed submarines are under construction, Sir Keir Starmer turned to the assembled workers before him and, becoming emotional, said: “This is where the story begins. The deterrence, our security, depends on you.”

The message was clear: nothing is of greater importance than national security in this era of geopolitical turmoil. Later the same day, after meeting officials from 31 allied countries at the Northwood military base, he warned Vladimir Putin that there would be “severe consequences” if Russia breached any putative peace deal in Ukraine.

This then was one face of Starmer’s Labour: uncompromising on national security and committed to rearmament and reindustrialisation. Donald Trump’s appeasement of Putin’s Russia and the weakening of the US security guarantee to Europe have given Starmer’s government a sharp injection of energy and purpose after its faltering start in power.

Starmer has chosen his side: he wants Britian to be leader of the pro-Ukraine group in Europe. Through his coordination of the European security response and ongoing attempt to build a “coalition of the willing”, he has demonstrated the kind of strategic international leadership not shown by Britian since Brexit.

We saw the second face of Labour on Friday morning when Ed Miliband was sent out on a tour of the broadcast studios. This was a rare media outing for the former party leader, who was largely hidden during the general election campaign. The day after John Healey, the defence secretary, had warned adversaries about the destructive potential of Britain’s nuclear weapons “to do untold damage” and Starmer had threatened Putin, here was Miliband promoting the government’s plan to fit more solar panels in schools and hospitals.

The timing of the announcement was eccentric, and Miliband neglected to say until asked on LBC that Britain was importing solar panels from China. Labour MPs were irritated. They complained they were being asked to send out press releases about solar panels being fitted at their under-resourced and overstretched local hospitals.

Miliband seemed even more buoyant than usual during his media round: he had just been voted the “most liked” member of the cabinet in a Survation poll of Labour members for the Labour List website.

I used to speak to Miliband when he was party leader, and he always seemed to me to be seeking to govern a country that did not exist or existed only in the overheated progressive imagination, which is why he had no answer to the rise of Nigel Farage’s Ukip. Our conversations ended abruptly in November 2014 when I wrote a column saying that, without a fundamental change of approach, he would lead Labour to defeat, which he did at the 2015 general election. The Brexit referendum followed soon afterwards.

Starmer is close to Miliband. He has few genuine friends in politics and Miliband, a fellow north London MP who smoothed Starmer’s way to a safe seat, is one of them. But Starmer knows as well that Labour has a Miliband problem. More than any other cabinet minister he embodies Labour’s progressive delusion, and many colleagues and party donors associate him with some of the party’s most abject defeats.

And yet as the Labour List poll shows Miliband is popular with members. They like his righteousness and passionate intensity. “The majority of our members,” one MP said scornfully when I mentioned the Labour List poll, “are exactly where we will go to die as a party; they are educated, ultra-liberal, urban.”

“The prestige of a nation is its reputation for power,” wrote Hans Morgenthau, the German-American realist. “That reputation, the reflection of the reality of power in the mind of the observers, can be as important as the reality of power itself. What others think about us is as important as what we actually are.”

Starmer and David Lammy, the foreign secretary, who spent part of last weekend in Washington with JD Vance and his family (they took mass together), understand that power must be projected, hence Starmer being photographed on a nuclear-armed submarine at the Faslane naval base and his visit to Barrow. They know inaction or excessive caution will further embolden Putin and the failure to confront Russian aggression will have consequences far beyond the borders of Ukraine. As Lammy often says to me, foreign and domestic policy have never been more inextricably linked.

The leadership of the 110-strong Growth Group of Labour MPs believes that solar panels (if made in Britian), net zero, nuclear submarines and fiscal prudence “can all make sense as a story about the new politics of national security”. But there are those who say that story is not being told by Miliband and the Department for Energy Security and Net Zero. He evangelises about renewable energy but seldom about new nuclear energy or about the potential of nuclear microreactors.

What’s needed is more honesty from the government about the necessary sacrifices the public must make in the short term to achieve the rapid transition to net zero in an age of rearmament and about our reliance on China for renewable supply chains. China will reach peak emissions by 2030 and aspires to reach net zero by 2060. Can the “home grown” new green industries, the hundreds of thousands of jobs and newly skilled workforce promised by Miliband be created in time for his 2030 target? The government is caught in a double bind: it wants rearmament and reindustrialisation and net zero, here and now.

Since becoming prime minister, Starmer has been in search of a story to communicate his government’s purpose and give definition to its policies. Now, he thinks, the story he wants to tell begins in the shipyards of Barrow-in-Furness. But this is only a beginning. The old progressive delusions endure in the party, and Labour seems trapped between two worlds, between the politics of a dead era which it can’t let go of and the new realities being forged through necessity in response to the war in Ukraine and Trump’s willingness to abandon America’s longtime European partners.

The tension between the old and the new, between soft left progressivism and a harder-edged, more conservative politics of security which defines this new emerging era, runs like a fault line through Labour, perhaps even through the prime minister himself. At least Starmer’s “security turn” as insiders call it is in earnest. But the incoherence will continue until Labour abandons – or world events force it to - its progressive delusions.