Daniel Craig as Bond in Skyfall

Right, pay attention, 007. After 50 years and 23 films, your franchise has achieved mission impossible. You have single-handedly made Britain feel good about growing old and answered the question first posed by Ian Fleming in 1953: how do you maintain British pride in a declining British empire?

“Where are we going?” asks M (Judi Dench) in Skyfall, the new Bond film.

“We’re going back to the past,” James Bond replies. “Somewhere where we have the advantage.”

Skyfall is about the past and its relationship with the present. It is about ageing robustly, as characters and as a country. It is about patriotism without cloying nostalgia, about acknowledging the past without being trapped by it, about getting the job done with grit and wit.

It is the perfect pop culture testament to Britain’s new-found post-imperial confidence, a fitting coda to a year of the Queen’s jubilee and Olympics in which the country took a long, hard look at itself and was quite pleased, in an understated, self-mocking, wry sort of way, with what it saw. Its motif is a kitsch figurine of a flag-wearing British bulldog on M’s desk, cracked and battered, but glued together and still whole.

Daniel Craig’s Bond is comfortable in his own scarred skin like no 007 before him. His stubble is greying. He can’t shoot straight, but he knows what to do, because “sometimes the old-fashioned ways are still the best”.

With Bond tied to a chair, the villainous Javier Bardem cackles: “Your knees must be killing you... England, the empire, MI6, you’re living in a ruin and you just don’t know it yet.” But he is wrong. This Bond knows perfectly well that he is not in his prime, that Britain is vulnerable, but 007 is still striving, seeking, finding and not yielding.

As a country, the knees are killing Britons and their stubble is greying, but they can still run pretty fast when the occasion demands. At the climax to the film, M (bless her cotton M&S socks) recites Tennyson’s Ulysses: “Though much is taken, much abides; and though/ We are not now that strength which in the old days/ Moved earth and heaven; that which we are, we are.”

Bond was Fleming’s answer to a country in imperial decline, a nation that had emerged from war victorious, but limping badly. Like many others, he was appalled by the legacy of war: the rationing, the slump in self-esteem, the withering of imperial self-assurance in the dreary, dowdy age of austerity. As an officer in naval intelligence, Fleming knew that British spy-craft and technological wizardry had been vital to victory; in the spy game, America had played second fiddle.

That world was fast disappearing when Fleming sat down to write Casino Royale. In the Cold War confrontation between the CIA and KGB, MI6 was increasingly a bit-player. Two years earlier, his brother Peter wrote of Britain’s need for a new fictional hero “with urbane, faintly swashbuckling sangfroid” as an “antidote to the restrictions and frustrations of life in England”.

Fleming created Bond as a counterweight to national insecurity, a character with the innate moral rectitude of the Second World War fighting the murky battles of the Cold War. In Bond’s world, Britain still calls the shots; the CIA needs Bond; the world needs Britain to save the world, as Britain had done during the war. “You underestimate the British,” Bond tells Goldfinger.

This was fantasy — inspired and enduring, but fantasy nonetheless — and increasingly divorced from reality as the Cold War intensified and the Bond series progressed. British intelligence was revealed to be riddled with spies. So far from relying on the superior British secret services, the CIA came to regard British spooks with mounting suspicion.

Fleming (and Bond) did their best to ignore the facts of the Cold War, and Britain’s declining power, yet Bond himself is prey to doubt. In From Russia with Love, he remarks ruefully: “At home and abroad, we don’t show teeth any more — only gums.”

Tiger Tanaka, the Japanese spymaster in You Only Live Twice, voices Fleming’s own fears that Britain has fallen into a post-imperial lethargy. Bond’s defence is, at best, quarter-hearted. “The liberation of our colonies may have gone too fast, but we still climb Everest and beat plenty of the world at plenty of sports and win plenty of Nobel prizes.”

That querulous defensiveness perfectly captures Britain’s post-war anxiety, as the old certainties crumbled. No such ambivalence was allowed to seep into the films: the film Bond is immune to doubt, his legend burnished in each new incarnation, with faster cars, better tailoring, improved violence, more girls, more martinis. In Britain, the films allowed the post-war generation to wallow in nostalgia, that most British of afflictions, recalling a time when Britain was great (or believed it was).

Outside Britain, the Bond legend enabled the British secret service to punch far above its weight for half a century. When George W. Bush went to war in Iraq, he specifically cited MI6 intelligence reports in his support: that was, in part, Bond’s legacy. Astonishingly, people around the globe bought into the myth that an Englishman with a Walther PPK and a nice line in repartee could save the world.

The film Bond is a cultural imperialist in a post-imperial world. But like all show-offs, his cool betrays a hidden insecurity. For most of his film incarnation, Bond is trying far too hard, straining to keep up the act, just as Britain has struggled to find a comfortable role in the post-war world.

But in Skyfall, Bond is Britain; not a mythical, made-up Britain inflated to bolster its historical self-image and impress foreigners, but a real Britain that has finally come to terms with what it is: stylish still, but a bit knackered; proud, but without hubris.

This Bond is funny, but darkly, not in the self-conscious, lounge-lizard one-liners of earlier Bonds. He is not on some moral crusade, saving civilisation with the aid of exploding pens, but doing his best to defend his country against some “bloody nasty” people — which is, of course, what MI6 actually does.

Something rather unexpected has happened to James Bond, and to Britain: suddenly, both have become believable, secure in both our past and our present: “...that which we are, we are/ One equal temper of heroic hearts/ Made weak by time and fate, but strong in will...”.