NEARLY six years ago, after downing too many of those awful stewed coffees you get at big conferences, I stood up and asked a stupid question.

I was at an international legal congress, in Glasgow. Its keynote speaker, unable to leave his then bolthole in Ecuador’s London embassy, was appearing remotely, his face blown up on a cinema screen.

Like Big Brother, I thought.

Here was Julian Assange, his trademark white hair combed back and his beard neatly trimmed, talking over a video link about the internet and the law. Nerdy stuff, not great copy.

So I took a mike. “Were Scottish nationalists paranoid to think the security services were involved in the independence referendum?” I asked the giant head.

A colleague, from a rival publication - relieved, he later said, at the chance to report something interesting - smiled in encouragement. But as I spoke, I imagined eyes rolling.

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“No, they are not paranoid,” Mr Assange responded, deadpan. “The attitude of the UK Government is that this is a national security issue, that Scottish independence is, in effect, a threat to the state.

"This mean that the full capacities of the GCHQ, for example, could be deployed.”

I sat down. I had a tale to tell.

But what is really intriguing, I thought – I still think – is why nobody ever tries to test whether this theory stands up to much scrutiny.

Me? I don’t believe it does. Mr Assange’s logic was not new, his is an old story. Some nationalists have been whispering for years – more often that not with an air of satisfied self-importance – that it somehow stands to reason that they are targeted by spooks because they want to break up Britain.

This spy mania is far from mainstream, especially now that the SNP runs Scotland and its leader is a privy counsellor, able to access intelligence.

But it is still there if you look for it; a sort of meta-excuse for political failure.

These last few weeks, amid lockdown fever and bitter – crazy bitter – feuding, it has spewed online again.

As the Alex Salmond saga reached its anti-climax in the Scottish Parliament, some Yessers tried to make sense of what journalists call a “psycho-drama” by inventing Bond thrillers.

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Type “MI5” and ‘Salmond” in to the search function of your favourite social media platform, and you enter a whole alternative reality.

There are supporters of Mr Salmond who don’t just believe the former first minister’s as yet un-evidenced allegations of a conspiracy against him by Nicola Sturgeon. They also see a hidden hand behind it: spies.

And there are fans of Ms Sturgeon who think Mr Salmond’s attacks must be part of some deep state plot to stall or stop independence by hurting his successor.

But ask anybody with any real experience of government, of secret policing, and they will tell you the same thing: cock-ups are bigger than conspiracies.

“It is not usually the secret services pulling strings,” says Phillips O’Brien, professor of Strategic Studies at St Andrews, “it is human beings screwing up.”

For Mr O’Brien, Scottish spy conspiracism echoes some of the dysfunctional social media politics in his native United States.

“There are great similarities with the Trump deep staters,’ he said. “Some people like to blame nefarious evil forces. Right now that tends to be the deep state or the intelligence services.”

He has a point. The security services make the perfect target for conspiracy theories. Because their work really is secret and they never challenge nonsense people say about them.

And that means nobody can definitively rule out they are up to no good.

But maybe instead of asking if the secret services are meddling in our politics, we should be trying to figure out what anybody would have to gain – and lose – if they were?

There is little to gain.

For starters, secret police are not necessarily going to be any good at politics: spin beats spies.

Just going by their ill-informed chat about Scotland, London Tories probably need a Herald subscription, not an agent in Holyrood.

And there is a lot to lose.

An illegal use of state secret services would be hard to hide – a point, to be fair, which Mr Assange made.

“It would be a very dangerous thing for the UK government to use its own intelligence services to interfere here,’ Mr O’Brien said. “Do I know for sure if they are or not? No.”

Are politicians capable of dirty tricks? Well, of course they are. Do they need spooks for that? Of course not.

That does not mean we should not be vigilant. The policing, intelligence and security services can cross lines, get things wrong and commit crimes just like the rest of us.

Think of the undercover cops who had relationships with women in protest groups. Scummy, that was.

We need more transparency, more scrutiny of spooks, not less. But here we collide with an unintended consequence of spy paranoia: an actual call to make secret services less accountable.

Since 2015, as a quirk of being the third party in Westminster, the SNP has had an MP, currently Stewart Hosie, on the committee which oversees intelligence and security.

Last month the work came under fire, from the SNP’s own benches. Kenny MacAskill, a former justice secretary, said it was “naive” to think secret agents were not operating in Scotland and questioned why Mr Hosie was part of the parliamentary watchdog. This, he said, writing on an anti-SNP blog, looked like “legitimisation by participation”.

Ask SNP loyalists about Mr MacAskill and they will sound more sad than angry. But he is badly wrong, irresponsibly so.

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There may be little evidence of spooks interfering in politics. But that does not mean politics should not interfere with spooks. The SNP should be scrutinising spooks, not fantasising about them.

Spy mania is toxic and those of us who call it out can expect to be smeared as agents. I have been. So have other journalists. After all, in the logic of the conspiracist, if you deny the deep state, you are the deep state.

But, as Scotland gets closer to potential independence, we ought to start getting smarter about intelligence.

Our columns are a platform for writers to express their opinions. They do not necessarily represent the views of The Herald.