The world is dividing up into hawks and ostriches. The autumn Budget will show which we are

The UK must commit to funding its armed forces, or risk alienating its allies in the US, writes former secretary of state for defence Penny Mordaunt

We need to build trust in what our armed forces, agencies and civil contingencies organisations are doing (PA)

Last week I took up an invitation to meet with some friends in the US defence community. The heat of Washington DC in the summer is a fitting place for such a get-together.

Things are hotting up all over the world.  During the week I was there, Taiwan was wargaming a Chinese assault. Ukraine was disrupting the rules of Russia’s war. Israel was preparing to defend against an Iranian attack. The Commission on the National Defense Strategy was circulating its report to Congress and the president of the United States. It called for increased spending.

And us? We trailed we would be drastically cutting the defence spending. If this is confirmed in the autumn Budget, it will be six days prior to the US elections. We’ve chosen to bury our heads in the sand.

US defence firms are already experiencing demand not seen since the height of the Cold War. Analysts are calling for yet more expenditure on top of that. The brutal fact is that defence spending is a zero-sum game. The less we spend, the more we have to depend on others. On either presidential election outcome, our ability to defend our interests is compromised.

Labour’s first Budget this autumn is the only opportunity they have to show their most important ally they are serious about playing their part in defending our collective interests. The new year will bring a new president, and the start of their budget cycle. Whoever it is, how can they argue for the levels of investment required when their key partners fail to match current spending levels?

The UK’s defence review may appear in the next 12 months. I look forward to it and am optimistic. Lord Robertson knows what he is doing and is a man to put country before party. His last review was highly consultative. We both have worked to get greater external oversight of security and resilience policy.

But much of his last review never materialised. If the argument now is that the UK “can’t commit a Budget because we don’t know what we need”, then the argument next summer must be “this is what we need so we must commit the Budget”.

But even if that review goes well, and Lord Robertson wins the argument, our government will have lost credibility if it forces through cuts in defence spending now. US advocates of strong defence will have to contend with accusations that its allies do not believe in burden sharing.

By slashing funding now, Labour lessens the chances of future US Budgets delivering an uplift. Add to that the damage done to UK defence by holding up programmes, slashing research and the advancement of key areas such as drone warfare and space. Such actions are short-sighted and will cost more in the long run.

The prime minister, the chancellor and the foreign secretary need to understand that the forthcoming Budget is a diplomatic signal as well as a fiscal event. They can choose to make it an encouraging one. Or they can show they are not a reliable partner.

Policymakers on all sides recognise we’re at an inflection point. Our strength and capability must be maintained or even enhanced, but no one wants to pay for it. Both the UK and the US face huge domestic pressures. The global economic recovery will be gradual and slow. US electors demand an end to America paying to be the police. It is easier to be an ostrich than a hawk.

Our leaders need to explain why decisions, events and outcomes in foreign lands matter in ours. For example, the consequences of a faraway conflict on your costs of living or illegal migration. Or the negative impact of Russian money laundering on the economy and wellbeing of the US’s rust belt or Britain’s “red wall” towns.

If Labour examines the return to our nation for every pound spent on defence, it will find it is a good investment. Our armed forces are an engine of growth and an escalator of talent. They are also a wise insurance policy.

I could have said the same about any previous Budget. But at this moment what the UK chooses has never mattered more. If we do not commit to doing all that is required to protect our national interests, then we can hardly be surprised when allies don’t either. That collective weakness will have grave consequences, not all of which we may be able to recover from.

We also need to build trust in what our armed forces, agencies and civil contingencies organisations are doing. Funding for these fundamentals needs to be appropriate and certain. Promises about “spending smarter” and defence reforms will only get you so far.

Guns or butter are not new choices. But neither is a choice between vigilance and wilful ignorance. We can demonstrate vigilance or bury our heads in the sand.