The aim of terrorism is to influence a group of people\ud
or institutions - the psychological target or targets - by\ud
attacking the appropriate physical targets in order to prompt\ud
the desired response. Several factors influence the selection\ud
of physical targets by non-state terrorist groups. These\ud
include the ideology of the terrorist group concerned, the\ud
strategy adopted by the group and its capabilities, its need\ud
to take account of external opinion - including that of\ud
supporters, the measures adopted to protect likely targets,\ud
and the security environment within which the terrorist group\ud
operates. In addition, decision-making is affected by the\ud
dynamics within the group which are in turn affected by the\ud
psychological pressures of clandestinity and the frequent\ud
risk of death or capture which many terrorists run.\ud
The relationship between these factors varies from\ud
group to group, which is inevitable given the idiosyncratic\ud
nature of most terrorist groups, and the different\ud
circumstances in which they find themselves. However, it can\ud
generally be said that ideology sets out the moral framework\ud
within which terrorists operate - and which determines\ud
whether terrorists judge it to be legitimate to attack a\ud
range of target. After this, the determination of which\ud
targets it will actually be beneficial to attack depends upon\ud
the strategy which the group has adopted as a means of\ud
achieving its political objectives. The determination of\ud
their strategic objectives depends upon the effects which the\ud
terrorists hope their attacks will achieve. Thus, strategy\ud
further refines the range of targets initially delimited by\ud
the group's ideology.\ud
The other factors mentioned tend to act as constraints\ud
upon the group, partly - as with security measures - in\ud
restricting them from carrying out the types of attacks which\ud
they would desire but also in encouraging them to carry out\ud
attacks on certain targets in the hope of gaining benefits\ud
such as the approval of their supporters, or of gaining\ud
publicity for their cause. Underlying all of this is the\ud
human factor, whereby relations within the group, the impact\ud
of psychological pressure, and individual differences in\ud
moral judgements may influence the targets chosen by\ud
terrorists