Dry run (terrorism)

A dry run or a test run is an act committed by a terrorist organization without carrying out any actual terrorism in an attempt to determine whether a technique they are planning to use will be successful. The dry run is part of the rehearsal for a terrorist act,^[1] and is often the immediate precursor to the attack.^[2] It may include attempting to smuggle weapons or other items to be used in the attack past a security checkpoint to determine whether this will be noticed, or monitoring the reactions of security personnel to the actions that would occur during a real attack.

The dry run is considered to be the heart of the planning stages of the terrorist attack.^[3] It is the method by which strengths and weaknesses in the plot are exposed to the terrorists, unforeseen obstacles can be detected, and the techniques are refined.^[4] Sometimes, multiple dry runs are conducted in an effort to perfect the ultimate attack.^[5]