Nature
Assassination can be defined as murder for a political end, often by an non-interested agent. It has been justified, sometimes even urged, as a revolutionary means, especially when no other way of overthrowing the establishment seems viable. As assassinations are stealthily carried out, the intended victim can never fully protect himself. Contract murders (by paid assassins) of people's spouses and other relatives, rivals and personal enemies are also well reported.
Background
The original "assassins" were members of a fanatical oriental sect, which held the religious belief that the imprisoned soul was released from the body after death by executing orders given by the Universal Soul. This belief allowed devotees to perform any deed without question or fear. The assassinations for which the sect was famous were originally committed against its persecutors, but developed into being committed for anyone willing to pay for such services. Assassins come to be trained for assassination: they were taught foreign languages and religious customs; the adoption and maintenance of disguises; and how to win the confidence of their intended victims. The name of the sect is derived from the Arabic 'Hashshashin' - hash eaters - because it was suspected that they intoxicated themselves prior to carrying out their missions.