King Charles' coronation needs to be grand, loud and very British – Alastair GJ Stewart

Critics have questioned the principle of throwing money at a "lavish" coronation for King Charles III in May.

For some, it's the principle of making a spectacle of an unelected head of state. For others, it's the vulgarity and tale of two cities in a cost-of-living and energy crisis. The late Queen Elizabeth II faced the same questions as her son. In the years just after the war, Britain's finances were propped up by an American bailout in 1946. Still, there was no media criticism of the coronation. On the other hand, Mass Observation surveys in February and May 1953 reported one in six expressing some direct criticism of the coronation.

Charles is the head of state. That necessitates acceptance of two realities: he is an international symbol for the country, and the occasions of state have less to do with satiating the public and everything to do with international perception. The British government should articulate clearly the diplomatic and economic reasons for the coronation being financially supported. A fuss with lots of flash and plenty of pomp should be made.

But why does it matter at all? Political scientist Joseph Nye introduced the "soft power" concept in the late 1980s. He argued that this rests on a country's "culture (in places where it is attractive to others), its political values (when it lives up to them at home and abroad), and its foreign policies (when others see them as legitimate and having moral authority)".

Consider the United States. American presidents are inaugurated with a star-studded ball and a military parade for the new commander-in-chief. The tradition dates back to the first inauguration when George Washington took the oath of office in 1789. If they were doing it for news headlines back then, they are doing it for omniscient media now. It is to send a message to friends and foes alike. "To be perfect for television," said Gore Vidal, "is all a president has to be these days.”

International relations are nearly always constructed around the presentation of power and, more often, the projection of it. It is about how a country wants to be seen. Heads of state, by definition, are meant to personify their country. It is why leaders lean into youth and vigour or age and wisdom. It's also why the more despotic leaders are covered head to toe in unwon medals with ridiculously inflated honorifics. It is an ancient trick, but they are not alone in it: President Emmanuel Macron, in his first speech at the Élysée Palace, emphasised rebuilding France's military credentials and the nation's self-confidence.

Somewhere in the middle is the uncomfortable reality of 21st Britain. British cultural power is far more significant and long-reaching than military or nuclear capabilities. Former US Secretary of State Dean Acheson famously commented in 1962, "Great Britain has lost an empire but not yet found a role".

The year 2012 was the triumph of Britain without an empire. The triptych of the London Olympics, the Queen's Diamond Jubilee, and the release of the nostalgic James Bond anniversary movie Skyfall combined perfectly to secure the win. The accomplishment of the Diamond Jubilee was the recasting of the monarchy as a cultural agent and not a political one. It works best when it stands centre-stage as part of Brand Britain.

The coronation of Queen Elizabeth II in 1953 cost £1.5 million, around £50m in today's money (Picture: Intercontinentale/AFP via Getty Images)

In 2017, Brand Finance reported the monarchy generated an estimated gross uplift of nearly £1.8 billion to the UK economy. This contribution included "the Crown Estate's surplus of just under £329 million as well as the Monarchy's indirect effect on various industries, such as tourism, trade, media and arts”. Given that the last coronation was in 1953 and cost £1.5m, which equates to around £50m today, that is not a bad investment for 70 years of diplomatic utility, tourism and brand promotion.

British soft power is a series of powerful cultural levers. For that reason, the Netflix exposé and TV interviews given by the Duke and Duchess of Sussex nearly sank the whole show. Most of the late Queen's Diamond Jubilee celebrations in 2012 were paid for by private donors and sponsors, with the taxpayer covering security. The Platinum Jubilee was £28m, with some of the cost borne by partner organisations rather than paid for entirely by the taxpayer.

No exact sum has been given on how much the coronation will cost, but it's been estimated at £100m. The Operation Golden Orb committee, which is planning the whole event, said that even though they were trying to save money, it would still cost a considerable sum.

British governments understand the importance of the monarchy. It is why Rishi Sunak effectively enlisted King Charles to help finalise the Winsdor Framework. The move was criticised for involving the monarch in a political furore, but it chimes with the notion that a crown is a political tool, not a political instigator.

The coronation has very little to do with who wears the crown. It has everything to do with showcasing British soft power and capitalising on an institution the world, much more than people at home, is obsessed with. Jubilees and celebrations may mark milestones, but coronations can pave the way for entire eras of British history.

As odd as the spectacle is, as ghastly a thought it is for any good republican even to support a penny of public money going to King Charles, it is very much in the national interest. What governments do with that is why we elect them, but for now, it is essential that the coronation be grand, be loud and be very, very British for the watching world.