take your pick: There are spies wrapped in Armani, and unwashed spies infested with lice.

What’s the difference between an agent and an intelligence officer?

   Not much if you’re from the United States.

   If you’ve graduated from Quantico, Virginia, and emerge as a fully fledged FBI investigator, you’re described as an agent. Agent Brown, Agent Smith and so on.

   Fiction and the media fudge the issue. Novels and newspapers refer to CIA agents and officers without distinction, as if the roles are interchangeable.

   Not so in the UK and some other European countries.

   Does it matter?

   That depends on who you are.

   Earlier today someone described me as having been an Intelligence Officer (IO) employed by Britain’s Secret Intelligence Service (SIS) during the Cold War.

   Wrong.

   I was an agent. Specifically, I was something called a Head Agent. That sounds far more glamorous than it is. I was a member of that secret and informal body of people known during the Thatcher years as SIS ‘contractual labour’. That doesn’t sound glamorous at all, and it wasn’t.

   These were people hired to work for SIS on contract because they had skills or access to a specific target that was required at that time. Or both.

   So yes, it does matter, if only for the sake of accuracy.

   What’s the difference?

   Intelligence Officers are by and large managers. They're posh. They wear suits and ties and work at desks in offices, like lawyers and accountants. They have careers. They are posted here or there. In SIS, an IO may spend three years abroad, working under diplomatic cover out of UK embassy. Then a stint back home, followed by another three years overseas. Their kids are mostly educated privately back in the UK at the taxpayers's expense.

    He or she might work under the diplomatic cover of Third Secretary Commercial, and later on, Second Secretary Cultural. After two or three foreign postings, the officers are assumed by SIS to have blown their cover, and henceforth will be ‘declared’ as Intelligence Officers to the intelligence liaison officer of the host country.

Even ambassadors have on occasion been IOs.

   I would suggest that an IO leads an interesting and comfortable life. He or she recruits and runs networks of agents and sub-agents. Sometimes just a single agent. Occasionally - and can I think of a couple of celebrated former SIS officers who managed to recruit none at all during their time in Moscow and Beijing. Those are known as ‘hard target’ capitals, incidentally.

   And the agents?

   Agents are in the field. It's where they belong. They’re the great unwashed. They didn't go to the right schools. They get their hands dirty. They don’t visit SIS headquarters on the Albert Embankment in Vauxhall. They don’t get invited to drinks or a coffee inside the local British embassy’s chancery in Islamabad or Berlin.

  They take most of the risk of exposure, capture, a beating, possibly torture and execution.

  In short, the agents have all the fun. The agents don’t take the credit for any successes they might achieve. The Case Officers do, and a gong thrown in at the end of it. Every Station Chief in SIS is awarded an OBE (aka Other Buggers’ Efforts) at the end of his or her tour.

IOs couldn't survive without agents, especially in SIS, which specialises in gathering human intelligence known as 'humint'. It uses its people to hunt other people.

  It doesn’t matter if the agent has smelly feet and bad teeth, didn’t go to the ‘right’ school and Oxbridge, and never held a commission in His Majesty’s armed forces. What does matter is the agent’s access to the target, whatever it is.

  Access is everything in intelligence work. The Unholy Grail

  I’ve often felt that the class divisions in the UK are reflected not only in the military, but in  the ranks of intelligence, also.

   As Head Agent, I served as a cut-out between the sub-agents I recruited and my Case Officer, a former British Army officer with three SAS tours to his credit, who drove a white, Long Wheel Landrover that stood out a bloody mile to my considerable annoyance. He could show off who he was as much as he liked, but that was no reason I could see to endanger my cover!

   In other words, a Head Agent protects his Case Officer and well as his own sub-agents. He insulates the one from the other. The latter wouldn’t know who I was reporting to. Most wouldn’t know which agency I worked for, and some would not be aware I was a spy at all (thought they’d probably suspect as much after a while).

   I remember debriefing a defecting general; we met several times and I had lots of questions each time.

‘You’re no journalist,’ he said at last, ‘because you ask too many professional questions and you already know too much about the military.’

   No-one’s perfect. Not that he minded. I think he preferred to speak to a suspected intelligence operative because it made him feel more important, and maybe because he thought his information would have a greater impact on policy in London.

   That’s why, incidentally, an intelligence officer working out of an embassy with a diplomatic passport who’s ‘declared’ to the host government still serves a useful purpose; word gets around pretty quickly in local diplomatic circles and people will deliberately seek him or her out to divulge what they know. Or maybe to defect. He or she is a walking magnet for other spies.

   So there are spies and spies. Those smelling of aftershave and wearing Armani and those like me with blisters and infested with lice.

  Which would you prefer?