Researchers from the RAND Corporation have found that an absence of clustering for terrorist attacks around trigger events since 1994 suggests that the threat of further terrorism after an attack should not affect every day life.
Using information from the Global Terrorism Database on attacks in the US and Europe between 1970 and 2013, the new report sheds light on the likelihood of further attacks following a significant successful terrorist plot: “When a terrorist event happens in a major city, there is no evidence that another event will happen in that city (or even elsewhere in the West) in the days or weeks afterward.”
The explanation offered by the report is that between 1994 and 2013 the pattern of the occurrence of terrorist attacks was statistically random rather than clustered. Furthermore, the analysis of the data reveals that “trigger events” such as a major attack, did not correlate to a surge of terrorist activity or the occurrence of deadly copycat attacks.
In light of this evidence, the report contends, “the threat of terrorism should not affect individuals’ behaviour and decisions in the United States and Western Europe—not even in the wake of a significant terrorist event.”
The timing of the report is crucial as western nations consider the best response to the increased threat of Islamist inspired attacks on their soil. The basic message that the history of terrorism has to offer in this case appears to be that daily life can and should go on.
However, there is a limit to what history can teach us in a period when trends in terrorism appear to be shifting. With its research period ending in 2013, the report hints at its own contemporary relevance, warning that the “historical analysis does not preclude the possibility that future attacks will follow a different pattern.” Although the period between 1994 and 2013 did not show signs of clustered attacks in the west, the rise of ISIS since 2011 and its growing intention to target the US and Europe may have started to shift the pattern.
In the past three years, it appears that new trends in global terrorism have emerged. For example, the increased use of social media by foreign terrorist groups to attract followers has exacerbated the fear of “homegrown” terrorist attacks in the west. The unprecedented number of individuals travelling to Syria and Iraq to join Islamist groups there also presents a worrying new trend that poses a long-term threat to the security of western nations.
These new trends appear to have reinforced a fear of clustered terrorist attacks despite the ‘random’ historical pattern revealed in the report. France remains in a state of emergency five months after the death of 130 people in the November Paris attacks due to the perceived threat of a second attack. Across the channel, the same attacks caused the UK government to consider increasing the terror threat level from ‘severe’ to ‘critical’. The recent airport and metro explosions in Brussels, which were supposedly conducted by the same network associated with the Paris attacks, raises legitimate questions about a new ‘pattern’ of linked attacks.
Although history often provides insights to the past that are of value to the present, the evolving threat of international terrorism means it would be foolish for policymakers to base security planning on what terrorists have been previously known to do.