The BBC's Cold War season has been uncomfortable -were we really that paranoid, that fearful; were we really so ungrateful for being on the right side?
- but also wonderful and inspiring, largely because it has been a chance to re-watch the 1979 dramatisation of Tinker, Tailer, Soldier, Spy (BBC Four, Tuesday, 10pm) with Alec Guinness effortless and elegant as George Smiley, the high chamberlain of spying.
Thirty-four years on from that version of John Le Carre's novel, the one-off drama Legacy (BBC Two, Thursday, 9pm) was a kind of tribute to it and largely succeeded in summoning up some of its atmosphere: the euphemisms spoken politely in clouds of smoke, the warnings whispered to the clink of whisky glasses, the painful sound of loyalties changing for all kinds of reasons - money, nationalism, sex.
It could have been a problem that Charlie Cox, who played the lead in Legacy, does not have the gravitas or the weariness of Alec Guiness, but that was really the point. Cox's character, MI6 agent Charles Thoroughgood, was at the opposite end of the career ladder to Smiley - he was a spy in training, a man who was just beginning to learn the twisted game of loyalty and disloyalty.
The 1970s, when Legacy was set, was a particularly good time to play the game because in those days the balance of loyalty was perhaps more uncertain than it has ever been at any other time in Britain's history. There was genuine fear in parts of the establishment that the loyalties of some British people - in the trade unions for example - lay not at home but in Moscow.
These divided loyalties were personified in Thoroughgood, who uncovers a plot by the Soviets to attack significant sites in Britain, including the Dounreay nuclear plant in Caithness, but more importantly for the young agent, he also discovers that his father was probably working for the other side. And what's worse than a lie told to you by your father?
The effects of the discovery were beautifully explored in Legacy, using some of the best techniques of Tinker, Tailor, Soldier, Spy: sharp dialogue, a lingering camera, a darkening sky. It was also pre-internet so there were none of those floating screens that M uses in Bond. Instead, there were files, and phials, which were filled with various antidotes in case the Soviets should try to poison Thoroughgood.
And, like the best espionage thrillers, there was something else important - something that the entire Cold War season has stirred up, particularly Dominic Sandbrook's documentary Strange Days (BBC Two, Wednesday, 11.20pm). It is a question for spies, for the spied-on, for all of us: how do you operate in a world that horrifies you, or in a country that makes decisions that shock you? There is probably only one answer: you just do the best you can and the rest of the tangle of loyalty and disloyalty, double and triple crossing, control and chaos, will just have to look after itself.