A key pillar of the outward-looking, optimistic Brexit case was that Great Britain was one of the world’s most prosperous and powerful countries with a global outlook to match. Getting subsumed into a regional bloc might suit some of our neighbours, the thinking ran, but not us.

With the Brexit vote now achieved, the Government has to start thinking seriously about what an independent Britain’s role in the 21st Century is supposed to be. If they intend it to be a significant one, then they should start preparing the ground for a sustained rise in defence spending.

Since the end of the Cold War, many European members of NATO have used the alliance, with its ultimate guarantee of US support, as an excuse to make serious defence cuts. Even Europe’s so-called martial cultures, the UK and France, have apparently left ourselves in a state where we can’t conduct sustained operations without American help, as Libya demonstrated.

This article sets out how successive Government’s have starved the Royal Navy of funds. Despite commissioning some state-of-the-art warships (which have their own problems), the author maintains that we aren’t buying enough of them to maintain the fleet’s previous capabilities – and don’t even have the sailors to properly crew those we do build.

Even impressive shipbuilding projects, like the two huge Queen Elizabeth class aircraft carriers, disguise the fact that we apparently won’t have the resources to put together a proper carrier group to protect more than one at a time. And some observers believe that this “decline and fall of British sea power” – much of which happened under the Conservatives – might not even be over.

World-class armed forces, particularly navies, are long-term investments. You can’t pare them to the bone when times are good because they take so long to build up again. Since the end of the Cold War, we have slashed defence spending. But the optimistic assumptions of the 1990s have not been borne out by experience.

Not only is the Middle East more dangerous than ever, but in Russia we have a much more conventional military threat – one that has already proven willing to seize land by force in Crimea, is sending warships through British waters, and is sufficiently threatening to NATO allies in Eastern Europe that Britain has deployed troops in Estonia.

Meanwhile, if Donald Trump is any indication America seems to have started to grow tired of footing the bill whilst European countries cut their defence spending to the bone. Trump doesn’t look like he’s going to win the Presidency, but it would be foolish to continue to leave British forces dependent on the US.

A fleet which can’t project strength everywhere we need it is no less silly than arguments that we should buy fewer submarines than Trident needs for a permanent at-sea presence.

Brexit gives us an opportunity to concentrate our minds on what we want Britain’s global role to be. We must recognise that an independently-capable conventional military is just as important to it as an independent nuclear deterrent, and be prepared to pay for both.