It was always going to be tough to (i) follow the tv series and (ii) compress Smiley’s odyssey of detective work, Kremlinology and reminiscence into 130 minutes. In fact, as I walked out of the cinema my first sensation was a hunger pang for the BBC series starring Alec Guinness. This I will act on – in good company it is a rich feast. I last watched it over a January week-end in North Norfolk in 2006, with intermissions for food and wine and walks out into the marshes.

I thought Tomas Alfredson did pretty well at the compression. And he built and sustained a fine atmosphere, though one wearied a little of some of the authenticating props – especially the same black cab passing back and forth, and the minis parked gratuitously in pairs. There were some memorable moments, such as the boozy rendition of the Soviet anthem at the Circus Christmas party, and Ricki Tarr’s lamplighting in Istanbul. And a set piece between Smiley and Toby Esterhase on a runway with a plane landing and taxiing towards them as a backdrop (“I want to talk about loyalty, Toby”) was enjoyable, though the script heavily favoured Smiley. Everything basically favoured Smiley and Gary Oldman undoubtedly delivered, producing a tightly-cloned rendition of Guinness.

But the visit to Connie tried too hard, and Prideaux! In the book and tv series Jim Prideaux is a rock of England – a point of wounded light around which lesser personalities swarmed and were illuminated, or died trying. But Mark Strong’s Prideaux was a greenhorn; he was too self-pitying a victim to weigh heavily on the film’s conscience. The story lacked the (admittedly low key) moral purpose of the novel.

Despite the gloomy lighting and seventies catering and cigaretting, TTSS failed to take us into the Cold War, where it undisputably belonged. What was at stake, Moscow’s ruthlessness and the frighteningly fine balance of  hostilities was not communicated. Le Carré was always more cloak than dagger, but Russia’s threat is all pervasive in his Karla novels. I missed this. I wish we had seen Karla – this would have given the enemy a face. Instead we had (at the end) Colin Firth as the traitor Bill Haden. Firth was good but not good enough – too straight and too young; the Circus leadership all felt too young to have made it to the top of a Cold War era national intelligence service (though Kim Philby was 51 when he was caught).

But it is easy to pick holes; the film critic has rights and no responsibilities, other than filing on time. And I am not a film critic, worse I am straying from my objective, which was to wonder what TTSS, as an interpretation of the state of our intelligence services, and our international relations, tells us about the present day …

Thought 1: we won the Cold War, which during the 1960s and 1970s was no certainty. TTSS reminds us how vulnerable the West once felt. In comparison to the 1970s, the UK is much, much better off: richer, more open, fairer and more secure. Worth remembering as we watch the crisis in the Eurozone and in our weaker moments wonder whether this is the end of something.

Thought 2: TTSS takes place in the midst of a grand contest between two different and conflicting models of government and social organisation. Both sides possessed great power, and huge resources of arms, money, territory, people and resolve. It was a fight to the death. The Cold War bears no similarity whatsoever to the present conflict with Radical Islamism.

Thought 3: the dividing line between politicians and the intelligence service has always been un-marked, trespassed and fought over. Although Tony Blair’s government went much further than others to bully SIS to his ends, and perhaps met less resistance than previous governments, the intelligence services are too sharp a tool for politicians to resist for very long the impulse to seize it and wield it in the direction of their enemies.

Thought 4: is the spirit of the Service – the priesthood of officers and agents, lamplighters and scalphunters, housekeepers and inquisitors that Smiley loved – gone forever? I have a hunch – and it is no more than a hunch – that it is less so than one might imagine. Le Carré’s later books have taken against it, largely because he feels that its pure calling – to “give the UK advantage, acting secretly overseas to make the country safer and more prosperous” – has recently been subverted by career politicians with a craven approach to President George W Bush’s unrelenting administration (see Thought 3). There is likely to be more gym work, fake tan and multi-cultural food in the canteen than there was several decades ago, and that is a good thing if SIS is to reflect the society it protects. But is the spirit still there? The spirit of the armed forces seems to endure, and this is a product of the people who share a common temper and aptitude, and a deep love of country still. Go to an NHS hospital, or a British Embassy somewhere overseas, and I believe you will find deep reserves of efficiency, common sense and humanity which are a product of the people who are working the machine. I guess SIS is still finding the same sorts of people it has always found, and therefore the essence of the place is still the same, despite the greater publicity, Britain’s tightened capabilities, the bruising failure in Iraq and the new threat of legal action. Why do I care? I’m not sure. Something about the priesthood … the vulnerability of men and women recruited to a service which espouses selflessness and service, tiptoeing slowly into the darkness. The dirty game between nations; the innate goodness of people, the things they will do for their country. Read this – it is wonderful.