Our hapless Prime Minister faces another storm not entirely of her own making: this time over defence funding. The Sunday Telegraph has publicised a report by the Henry Jackson Society, a think tank, which starkly illustrates that spending 2 per cent of GDP on defence (if that were ever achieved) does not produce the ‘strong defence’ that Mrs May declared an ‘important priority’ in 2016.

The Ministry of Defence has been in turmoil since the collapse of the Warsaw Pact and the Soviet Union, and the end of the Cold War. This is in part unsurprising. The certainties of the same old adversary deployed a few hundred miles from the Channel (and surrounding Berlin) gave a focus to equipment procurement, strategy and tactics. It also focused political thought. It was not a panacea, as the challenges of liberating the Falkland Islands revealed, but it gave coherence to policy. Since then there has been chaos, as illustrated by the number of defence reviews. During the Cold War (1945 to 1989) there were six, about one every eight years. Since 1990 there have been seven, more than one every four years. The most recent (the Strategic Defence and Security Review 2015) is already in trouble as it did not envisage Brexit or the decline in value of sterling (much defence spending is in euros and, particularly, dollars).

While these problems cannot entirely be blamed on Mrs May, it is her job to solve them. As politicians are happy to parrot in the good times, the defence of the nation is the first duty of government. These aren’t good times – but that does not remove the duty. No one forced Mrs May to become Prime Minister; now she needs to earn her pay and deliver the promised strong defence.

We’re leaving the EU, we’re the fifth-biggest economy in the world and, courtesy of the Commonwealth, one with more global influence and responsibilities than most nations. We need to be able to project hard and soft power, as most of the 17million who voted for Brexit understand and welcome. That means more ships, probably more aircraft and getting a grip of the Army by giving it clear mission priorities.

That means you, Mrs May, not Defence Secretary Gavin Williamson, need to explain to Spreadsheet Phil that funds have to be made available. You and he conjured £40billion out of nowhere for the Brexit divorce – that’s more than the entire defence budget of £37billion – so it’s possible. If you are pushed for options, remove the 0.7 per cent of GDP lock that your predecessor gave the international development department (also known as the department of blank cheques).

Which is not to say that throwing money at the MoD will solve its problems. There has been a 20-year brain drain as able and intelligent officers take redundancy rather than support the ‘mismanagement of decline’, as one departing top-notch Colonel put it to me. You need to find a Cardwell or Haldane to get a grip on the whole edifice. That figure may be Gavin Williamson, but if it isn’t you’ll need to find one somewhere – quite possibly outside Westminster.

Yes, it’s challenging – although not entirely unsurprising – that this is happening on top of Brexit. But that goes with the job. On the upside, it’s a unifying cause in your party, and you badly need one of those. Surely you can deliver the proposition that ‘Brexit means Brexit, which means we need strong defence’? Time is running out for you and your lacklustre Parliamentary colleagues. Get a grip on your Cabinet and do your job.