If you shudder I shake my head – at the thought of the Foreign Office dealing, as you write, with “security”. David Milliband is in Tblisi today, two weeks after David Cameron and the FCO – much like over the Lebanon crisis in 2006 – clearly failed to anticipate the crisis or provide the necessary advice once it broke out.

Secondly, I’m concerned with the idea that the FCO should somehow deal only with high-faluting things like “security and climate change”. Unless the FCO deals with things that matters to people – especially jobs, tourism and investment – then support for the diplomatic corps will fall further.

But, as you say, the FCO should only focus on things that give a return on investment. You contend that trying use the Olympics to brand Britain will not work. Like you, I’m no expert on this issue, but think nations can achieve a lasting legacy and build on their brand using the Olympics and sports more generally.

Barcelona did it. Ten years after the 1992 Barcelona Olympic Games, 40,000 people gathered in Montjuic stadium to celebrate the anniversary. Why? Because before the Olympics Spain was thought of as a European backwater; today it’s seen as a hip, high-design playground. Most Spaniards believe the Games played a key role in this.

You concede that tourism is the exception to the financial benefits from hosting the Games, but it’s worth showing just how big an exception it may be. In Lillehammer, host of the 1994 Winter Olympics, saw tourism soar 43 percent in the four years preceding the Games. Calgary saw a similar boost. Between 1972 and 1985, the annual growth rate of international visitors to Calgary held steady at about 0.25 percent. In the three years leading up to the 1988 Winter Olympics, tourism jumped to 8 percent, then to 12 percent during 1988. The city then held on to an increase of 3.25 percent annual growth for the next five years.

True – the Calgary Olympics lost money, but that simply goes to undermine your final point that the Olympics promote themselves. They don’t and need to be managed well to succeed both as a branding exercise and financially.

Then there are the more subtle effects. What about South Africa’s Springboks – did they not underscore the country’s successful transition? Nelson Mandela thought so. I can think of many other times when sports made a difference – as in the case of the ping-pong diplomacy between China and the USA in 1971, which changed the perception (or brand) of both countries. But I digress.

In quick succession let me deal with your points 3 and 5.

You go on to say governments aren’t good at branding small things – but by what definition does the world’s largest, most expensive, most televised event become small?

You then assume that nation-branding somehow needs to be jingoistic or based on exclusive values. But while you wait for World Government, I will work with what we have – the nation-state – without assuming that the promotion of British values necessarily undercuts everyone else’s values or prevents us from working together.

Where I do think we can agree is the view that countries can no longer simply promote themselves – as the failure of the Australian tourism campaign shows. Today, I suspect they have to work on broader issues. The “Make Poverty History Campaign” was the most naïve and bound-to-fail initiative ever invented – but it did wonders for Britain’s image. Tony Blair understood that and I’m surprised that Gordon Brown has not fronted a similarly-styled “Save the Planet” campaign on climate change. I think the Olympics can be used in such a campaign for the benefit of Britain and more broadly. That’s all.

Some reasons (in no particularly logical order):

1. There’s little evidence that sporting events have a long-term impact on a country’s brand. Nation branding is not my area, but I believe the evidence suggests a brief uplift is followed by a return to previous levels.

2. Neither is there, I believe, much evidence to show a significant impact on trade – though tourism may be an exception (Even here it can make sense to try and make sure people actually come the country in the Olympic summer – fear of crowding and higher prices will drive many away).

3. Governments aren’t very good at branding small things. They certainly have little to boast of in many doomed efforts to rebrand their countries.

4. Most importantly of all, we have much more important issues for our diplomats to focus on – security and climate change to name two. These are clearly government’s business, but are currently done badly.

5. Relatedly, a focus on branding (and in the US’s case, a puppyish need to be loved) drives us towards narrow self interest, rather than to focusing on shared platforms and joint responses to the risks characteristic of an interdependent world. Do we need another reason to shout at Johnny Foreigner about how great we are?

6. And I suspect the Olympics promotes itself. The UK will spend 9bn or so in providing a month-long sporting party for the rest of world. A certain amount of gratitude will, I think, naturally follow.