There was, depending how you do the accounts, some extra money for defence in Labour’s Budget, but the fundamental problem remains: social security continues to trump national security. At a time when the threat from Russia is growing and the war in Ukraine continues to expose the brutal realities of modern conflict, this is a dangerous gamble with Britain’s future.

John Healey has promised to plug the £4.7bn hole in the defence investment plan left unfunded by Sir Keir Starmer. That is welcome, but it should not be regarded as anything more than a stopgap. Filling a hole is not the same as building a credible defence.

There are expectations of additional funding beyond that commitment – and this is vitally necessary if we are to have assurance of our national survival in today’s dangerous world. However, the crucial questions remain unanswered: how much more will be provided, where will the money come from, and when will it reach the front line? Our Armed Forces cannot fight on promises, Treasury accounting tricks or political rhetoric. They need equipment, ammunition, personnel and the industrial capacity to sustain a war.

The Conservatives have demanded a commitment to spend 3 per cent of GDP on defence by 2030, arguing that Mr Healey should resign if he fudges the issue rather than properly funding that target. Let us be clear: that target has not been reached and there is no plan to do so. Achieving it would require an additional £11bn in 2030 alone. The Government’s longer-term pledge to our Nato allies is to reach 3.5 per cent by 2035. The next decision on funds and timings is expected in next year’s Spending Review. But the threats facing Britain will not politely wait for the Treasury to finish its calculations.

Volodymyr Zelensky has made that point with characteristic directness. On the eve of the Budget, the Ukrainian president urged Mr Healey not to delay increases in defence spending in an interview with The Sun.

“Can the United Kingdom trust Russia or not?” he asked. “If not, defence needs to be 100 per cent the priority.”It is difficult to argue with the logic. President Zelensky has spent nearly five years confronting the consequences of Vladimir Putin’s aggression. He knows better than most that deterrence is not built on declarations of intent. It is built on military strength, industrial resilience and the demonstrable willingness to defend your country.

Mr Healey himself resigned as Sir Keir Starmer’s defence secretary amid a row over funding, accusing the Treasury of being unwilling to provide the money required. His subsequent promise to fill the £4.7bn gap is therefore particularly significant. Yet if the Government continues to treat defence as a problem to be contained rather than a national priority to be funded, the underlying crisis will remain.

Britain’s predicament is not simply about how much we spend, but what we get for it. Years of underinvestment have left serious questions about the readiness of our forces, the availability of munitions and the ability of British industry to replenish equipment at the speed a major conflict would demand. Money announced now will not instantly produce tanks, missiles, drones or trained soldiers. These capabilities take years to develop, procure and integrate. Kicking the can down the road to next year’s Spending Review adds to the delay. Doing nothing has an effect.

Meanwhile, Russia is waging war against Ukraine and pursuing a broader campaign of intimidation, sabotage and disruption against Western interests. The precise timing and scale of any future threat to Nato cannot be known with certainty. But the lesson from Ukraine is unmistakable: the price of preparing too late is measured in lives, territory and national sovereignty. Fighting a war also costs much more than deterrence.

The Government will rightly argue that it faces difficult choices over public spending, welfare and the cost of living. No one should pretend that these pressures are insignificant. But national security is the foundation on which the very existence of the government rests. There is no future for the NHS or the welfare state if the country cannot protect its citizens, infrastructure and freedom from external aggression.

Nor is defence spending simply money diverted from domestic priorities. Properly directed, it supports skilled jobs, advanced manufacturing, technological innovation and the industrial base that Britain will need in a crisis.

Funding the defence investment plan (DIP) is, it seems, a notable achievement. But the DIP is not enough by a long chalk. Unless it forms part of a credible, properly funded and transparent plan to rebuild Britain’s military capability, it risks becoming another temporary fix in a defence system that has been asked to do too much with too little for too long. Britain needs a clear timetable, properly costed commitments and a defence budget that delivers the forces our country requires, not merely the figures ministers can accommodate.

Let us hope Putin is not watching too closely. He will understand the difference between a country that is serious about defending itself and one that is still arguing about whether it can afford to do so.

Make no mistake: not only do we not have national security today, we do not yet even have a plan for achieving it.