In crucial respect, the spy trade is different from almost every other business on earth. Its successes – an enemy agent turned, a disaster averted by skilled intelligence gathering – are by definition secret. When we learn of them, it is often years after the event. Of things which did not happen, we may never learn at all. So when an intelligence agency starts making headlines, it's usually because of a failure.
That principle holds good once again in the increasingly lurid affair of Mahmoud al-Mabhouh, the Hamas commander murdered last month in Dubai by, it is widely assumed, Israel's Mossad organisation.
Yes, in narrow terms, the operation was a success. A targeted assassination had been carried out, a senior figure in a group committed to the destruction of the state of Israel had been eliminated. But – again assuming Mossad was responsible – the gains are surely outweighed by the losses: international uproar, the straining of relations with important allies, further evidence that Israel behaves as madly or worse than its enemies. Of course the hubbub will fade. But would Israel have preferred the whole thing had passed without much notice, as until this week it seemed set to do? You bet.
That is of course, if it was Mossad. James Jesus Angleton, the brilliant but paranoid head of CIA counter-intelligence, used to talk about the "wilderness of mirrors" in the spying trade that could drive a man close to madness – and in his case did. Angleton was a Cold War warrior; his business was assessing human loyalty: whether defectors were genuine, whether your people were working for you or for the KGB. He ended up believing a Russian disinformation campaign was taking over the world.
In the Middle East, the mirrors are different, but the wilderness they create is no less disorienting. Was it Mossad? Or was it foes of Israel who deliberately made it look like the agency's work, in order to discredit Israel. But then again could the legendarily efficient Mossad really have left so many clues? To which the answer is yes, if you subscribe to the cock-up theory of life. Or were the Israelis quietly working with the Fatah movement, Hamas' rival for control of Palestine, on the basis of my enemy's enemy is my friend? Or – a thesis supported by the absence of his usual retinue of bodyguards – was al-Mabhouh the victim of an internal Hamas power struggle, in which Israel was set up to take the blame?
One thing though is certain. Targeted assassinations are a fact of life, and not only in the Middle East. Israel's staunchest ally, the US, has used them in the so-called "war on terror". That indeed may be why Washington has remained conspicuously quiet about the Dubai affair, even after it emerged that five of the suspects had credit cards issued in the US. Last summer the CIA was swept up in controversy over a secret 2001 presidential order by George W Bush that purportedly set up special hit teams to hunt down and kill al-Qa'ida terrorists. Briefly, there was a huge fuss over whether the order breached a quarter-century ban on CIA assassinations of foreign figures, imposed by President Ford in 1976.
The CIA quickly let it be known the plan was never carried out. But the difference between targeted assassinations by human hand and those indubitably being carried out today by remote controlled drones is only one of technology, not morality.
In Russia too, assassinations on foreign soil are a constant of history. More than 60 years after Leon Trotsky was murdered in Mexico on Stalin's orders, many people believe former KGB agent Alexander Litvinenko's old employers arranged a similar fate for him in London. The KGB's "wet jobs" division that handled such business is said to have been phased out. But Israel, the US, Russia (and probably not a few other countries) will continue targeted assassinations. The real trick is keeping them quiet.