It's embarrassment, isn't it? That's the only explanation. It's good old-fashioned British horror of anything that might provoke any kind of controversy, any public display of untoward emotion.
That's why the local authorities of this country have displayed such glacial indifference to the 13,000 servicemen returning this autumn – hundreds of them grievously injured – from the battlefields of Iraq and Afghanistan.
That's why the Chief of the General Staff, Sir Richard Dannatt, was driven to his sad complaint last week.
That's why there will be no parties or treats for men and women who have given so much.
That's why no one is laying on a parade. It's nothing to do with our so-called stiff upper lip, or dislike of show. Don't give me that guff.
This is a nation awash with cheap sentimentality, a nation that went into an ecstasy of mourning for the death of the Princess of Wales, and which is still far more interested – to judge by the news coverage – in the fate of one four-year-old girl than in the losses and injuries now being sustained by the entire Armed Forces.
But when British politicians, local and national, try to imagine any public act of thanksgiving for military sacrifice, they go into a kind of swoon.
They close their eyes and see maimed soldiers going past – some of them in wheelchairs – and they imagine the sudden shock and distress on the faces of passers-by, as they are confronted with the real price of war.
The politicians worry that it could all go so horribly wrong: shouted denunciations from the public, or – more disturbing still – from the veterans themselves.
Worst of all, they worry that any such parade, or any gesture of comfort and reassurance to the returning soldiers, could be construed as support for the war, a war that is now so colossally unpopular with large sections of the British electorate.
"Support for the war!" they think. "That would be appalling!" And so we collectively and institutionally exhibit a chilly reluctance to say thank you to thousands of young men and women who have made huge sacrifices on our behalf.
That reluctance is born of embarrassment, and it is based on a complete misapprehension. Not so long ago, my friend and colleague Richard Benyon took a VIP party to Newbury races and, since he is the local MP, they handed him a microphone at the start of the afternoon. He introduced his group to the rest of the racegoers. Some had their heads or limbs in bandages. Some could not walk.
He got as far as saying, "These are servicemen wounded in Iraq and Afghanistan," and was drowned in a roar of applause – a display of public support so unabashed and wholehearted that for a second he was overcome.
He reckons it would be the same across Britain, and that football fans at Highbury or Craven Cottage – or at least the overwhelming majority – would feel the same; and yet the idea of such public celebrations fills the authorities with apprehension.
When he came to organise the day, he was puzzled by the apparent attitude of the MoD, and its obsessive desire to keep the media away.
Of course, the Government wants, quite rightly, to protect badly traumatised personnel from journalistic intrusion. But Richard had the feeling that there was a real nervousness at work, an anxiety about the sight of large numbers of injured personnel.
It seems very likely that some people in the ministry may be worried about the political impact of such a sight.
Perhaps they fear that the very spectacle of such tragically injured young people will breed further hostility to the war; and yet – if those are indeed the motives – that shows a deep misunderstanding of the public imagination, and of the needs of these soldiers.
According to Mr Benyon – who served in the Greenjackets – veterans of the Iraq and Afghanistan conflicts now feel as alienated from society as American GIs returning from Vietnam.
And yet America has learned the lesson of Vietnam and the gulf that was allowed to grow between society and those who fought a deeply unpopular war.
Drive around America and you will be astonished by the number of yellow ribbons or bumper stickers, urging Americans to "support our troops".
You can drive around Britain for months and will not see a single poster, sign, badge, lapel pin in any space in this country – public or private – urging solidarity with our forces.
On the contrary, you will see the exact opposite. You will see endless graffiti confirming that British troops are fighting a war that most people vehemently disapprove of.
The result is that we are depriving our soldiers, especially our injured soldiers, of one of the most important parts of the healing process, and that is the sense that they are valued for what they have done, and they are welcomed back with honour by the rest of us. That, surely, is the least we can offer them.
They were not responsible for the deceits of the Labour Government. They can't be faulted for the failure to find any Weapons of Mass Destruction, or the failure of the Pentagon to plan for the aftermath of the war.
They were sent out by our democratically elected Government to fight for what they honestly construed to be our good and our safety. Some of them have fought harder and longer than any British soldiers since the Second World War.
Many have sustained injuries more terrible than in the past, for the simple reason that modern medicine allows them to survive.
They are owed the thanks of all of us, and I am sure the public is more than willing to give it. For all those who would like to show their appreciation, a new appeal is being launched on Monday, called Help for Heroes. Among other things, the objective is to help raise funds for the rehabilitation centre at Headley Court, near Leatherhead, Surrey.
Whatever the anxieties of the local authorities and the bureaucrats, I am sure the activities of this organisation will be well supported.
People have no difficulty in making a distinction between the rights and wrongs of a war, and the heroism of the troops we send out to fight it.
• Boris Johnson is MP for Henley
