When you are reading a spy novel set during the cold war, it's impossible not to think of James Bond, whose books were originally published between 1953 and 1966. Most striking is the difference between Fleming's smug dilettante and any story that deals with a more realistic take on the subject.
The problem is that James Bond doesn't actually do much spying. No spending months infiltrating an enemy country under a false identity; he's always quick in there, steal the plans, sabotage the death ray, kill the bad guy, get the girl, and out before a real spy had reached the outer perimeter in the guise of a nondescript worker. And he's always so flashy and high profile where a real spy is the exact opposite.
And then there's the whole "license to kill" business. He's a spy. It's a very dangerous business. Any spy undercover in hostile territory surely has the authority to protect themself by whatever means necessary, up to and including killing people, so why does 007 get a special certificate for it?
And then it struck me, that's not an extra qualification, that's his job description. It makes sense that they'd want the enemy to know he was responsible, that he'd be sent in for quick jobs, that so many people die when he's around. Of course it would be terribly unbritish to admit what he was really up to, so it's always couched in euphamism and the pretense that he is a regular member of the department, but it's obvious when you think about it. James Bond isn't so much a spy as an assassin.