In Frederick Forsyth’s classic 1971 thriller The Day of the Jackal , the lead character explains why paying someone to murder your enemies for you is such a good idea. “A professional does not act out of fervour, and is therefore more calm and less likely to make elementary errors,” he argues. “Not being idealistic, he is not likely to have second thoughts at the last minute about who else might get hurt.

.. and being a professional he has calculated the risks to the last contingency.

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