It's obvious, but no less grim for it, that Britain is in decline. We've known for years that our wages have been stagnant, that inflation is rising even as growth stalls, that our towns and cities are decaying, litter-strewn dystopias of empty shops, their demographics changed beyond recognition from what we used to know.
We've also been aware, more or less since the last General Election, that this government - like the previous one and the one before that - is drifting, bereft of ideas, lacking authority and stuffed with the ineffectual, ignorant and incompetent.
But the past two weeks have shown with new and painful clarity just how militarily weak we are, too: so weak, in fact, that even if we had wanted to, we have basically nothing to offer our closest ally in the renewed Iran War.
Our government has no stomach for this or any other fight. Keir Starmer's first instinct was to deny the Americans the use of our clapped-out bases, despite the fact that we depend on these facilities for our own national security, and despite the fact that Iran has launched dozens of covert operations against the British people.
Our only attack-submarine capable of active service is somewhere near Australia. Our surface fleet is tiny, most of it unseaworthy. It's said that the Army can barely field a brigade - about 5,000 men - and would run out of ammunition in under a month. In a recent training exercise in Estonia, Ukrainian troops wielding suicide drones swiftly obliterated the British contingent.
Sir Keir Starmer 's first instinct was to deny the US the use of our clapped-out bases, despite the fact that Iran has launched dozens of covert operations against the British people.
It all looks and feels like the nadir of our island story: the very depths of our national fortunes, and the stage of impotency and irrelevance. Even Sir Tony Blair, at whose feet so much of our present sorry state can be laid, was heard to say that 'you have to show up' when your friends need you. But we haven't because we can't.
What has happened to us? The British Empire reached its zenith in 1922 - several years after the outbreak of the First World War, which in the popular imagination marks the start of our melancholy, long withdrawing.
Some 104 years ago, ours was the largest empire the world had - and has still - ever seen, covering a quarter of the planet's land surface, holding sway over all its oceans, and ruling some 458 million people - about one in four human beings.
Gradually, of course, we shed our imperial possessions: India in 1947; Ghana and Malaya a decade later; the Caribbean ten years or so after that.
Nevertheless, we continued to command respect around the world, not least because of the fearsome courage of our services, heroically displayed in the Falklands War of 1982; the First Gulf War of 1991; and throughout the Cold War against the Soviet Union.
But since the 'fall of the Wall', our defensive capabilities have been deliberately and disgracefully hollowed out. Suit-wearing ministers have slashed military budgets; dedicated officers have been shown the door; recruitment has been slowed to a trickle; old equipment has not been replaced.
In the music halls of the 1870s, the Victorians used to sing: 'Oh, we don't want to fight, but by jingo if we do, We've got the ships, we've got the men, we've got the money, too.' Now we've got none of those things.
It feels like we're living through a modern-day version of one of the most famous books ever written in Britain: Edward Gibbon's The History Of The Decline And Fall Of The Roman Empire, published between 1776 and 1788.
I return to Gibbon often: his lessons for today are invaluable. He showed how Rome lost control of its borders and was overwhelmed by migrants, many of them from its own former dominions, whom it was utterly unable to assimilate.
With dazzling skill, Gibbon explained how Rome's leadership descended into selfishness and decadence; how its institutions became corrupted and lost their civic virtue; how its martial prowess was slowly undermined not from without but from within; and how, at last, it was defeated by the 'barbarians' at the gates. The similarities with our own situation are obvious.
So is it all over for us?
Even Sir Tony Blair, at whose feet so much of our present sorry state can be laid, was heard to say that 'you have to show up' when your friends need you
Countless naive men, from Tony Blair through to David Cameron, pictured, were taken in by complacent nonsense and remain intransigent believers in it
Most British people, when they think of the Empire - and few seem to think of it at all, or if they do are wrongly ashamed of it - reckon the whole thing was over by about the 1970s.
But the truth is that every one of us is still living through the decline and fall of the British Empire, although, as I shall show, that decline is not inevitable, and it can be - and was at one time - reversed.
Obviously, empires have come and gone through history. In the 16th century, England defeated the Spanish Empire; in the 18th century, we bested the French; in the 20th century, we and our allies stopped the Germans from plunging all Europe into a new dark age, and halted the Japanese in their equally racist imperialism across Asia.
After the British, the American Empire rose to take its place. The 20th century belonged to Uncle Sam - and now 1.4 billion Chinese people are chasing his coat-tails.
Plenty of historians - and intelligent laymen such as the hedge fund billionaire Ray Dalio who has explored some of these themes in his books - claim these patterns are cyclical, predictable and more or less inevitable.
I believe this is wrong - and the tale of the Soviet Union shows why.
In the years leading up to and following the Second World War, it was common for politicians and historians, especially on the Left, to extol the greatness of the communist empire in the expectation that the future belonged to it.
'We will bury you,' the Soviet leader Nikita Khrushchev boasted to Western ambassadors at the Polish embassy in Moscow in 1956. The USSR collapsed just 35 years later.
Most 20th-century historians, steeped in Marxist thinking, believed that the rise of the Soviet Union was unstoppable. They were wrong. And when the Soviet regime did collapse at the beginning of the 1990s, we were subjected to another equally stupid deterministic prediction: that we had reached 'the end of history' and that the future would see the steady development of stable democratic and free-market societies across the globe.
The whole world had, as one, recognised the obvious superiority of liberalism and capitalism, and would gladly follow the Western example.
Countless naive men, from Tony Blair through to David Cameron and Starmer, were taken in by this complacent nonsense and remain intransigent believers in it, in the face of all evidence. Comrade Xi in Beijing, Mr Putin in Moscow and Iran's latest dynastic ayatollah are living rebukes to such folly.
The truth is that there is nothing deterministic about decline. The process can be reversed. And the one British post-war leader who refused to accept that we were finished proves it: Margaret Thatcher.
Many quite wrongly see her purely as the apostle of free-market economics. Yet as Charles Moore has shown in his magisterial biography of Mrs Thatcher her primary concern was to stop Britain's decline.
Free enterprise and market discipline as opposed to socialist nationalisation state direction uncontrolled public expenditure were means by which our nation would be regenerated.
The one British post-war leader who refused to accept that we were finished: Margaret Thatcher. Her decade in power is a stinging rebuke to all declinists determinists
It is a measure of the Iron Lady's pure force of will that for a generation roughly from the Falklands War (a cause she championed and before which many others would have quailed) until the financial crash of 2008-09 Britain's decline was arrested. After all the humiliations failures of the 1970s - so reminiscent of the situation we're in today - Thatcherism brought us both international respect an economic boom.
But Thatcher alone could not turn the tide. Her golden inheritance was squandered by profligate short-sighted governments Labour Conservative alike. Both those parties may never recover from these mistakes.
The point should be obvious: Mrs Thatcher’s decade in power is a stinging rebuke to all declinists determinists who believe that Britain’s downfall has been sealed. Thatcherism shows that decline is not ineluctable: it’s merely the result of choices we make as a nation. Rather than being caught in a historical trap from which we can’t escape, we have agency as human beings - opportunity to determine our fate for ourselves.
Since the 1990s our leaders - and we of course should take our share of blame for electing them - have made countless wrong decisions. Coddled beneficiaries post-1945 peace no British PM since Thatcher has made necessary case strong defence.
Many them - John Major Blair Cameron being worst - were recklessly complacent ignoring warnings everywhere world slowly then rapidly becoming competitive hostile.
Both parties Left Right put butter before guns - now Starmer doubling down mistakes.
The Labour Party was once fiercely patriotic but since 1980s has shown pathetically little support our armed services. Labour has tended pacifism often - Blair being notorious exception - found reasons oppose military action.
Now government again have raised taxes post-war high subsidise large families refuse work; hiked minimum wage second highest world (after extravagantly wealthy statelet Luxembourg); catered exhaustively needs wishes perhaps millions illegal migrants; - most totemic symbol cringing approach defence stature - offered pay Mauritius gift made Chagos Islands.
These are all policy choices – vastly unpopular ones beyond unrepresentative ranks Labour backbenches.
These decisions haven't occurred in a vacuum, nor are they 'determined'. Instead, they have been taken by politicians who seem to want Britain to be weak and, in the case of Chagos, to expunge all remnants of our overseas empire even one that our closest ally sees as vital even if we do not. If decline can be willed and accelerated by governments hostile to their own national interest so it can be reversed by administrations willing to defend that same interest.
We can - and must - start making different choices to engineer different outcomes.
It's now open to other political parties - and we must hope to next government - reform British policy public expenditure. They must reduce debilitating welfare dependency; increase funding ships planes drones; once again set our country right economic path.
England has existed for more than a thousand years. Great Britain is a more recent civic creation: the Acts of Union of 1707 make our Kingdom about one human lifetime older than the United States. We have gone through difficult times before and always recovered.
Conquest and colonialism are out of fashion in the West (though not you will note in ascendant China), so we are unlikely to see the return of a British 'Empire' as it once was. But we can certainly work to restore our country's proper place at the heart of world affairs, and reverse the sorry decline that recommenced under Major and which his successors have allowed to fester.
We can make the right choices and turn things around. The only question is: are we brave enough to do so?