ABSTRACT
In the 1990s there were a number of attempted acts of mass killing. Al-Qaeda came close to achieving it at the World Trade Center in 1993, as did Aum Shinrikyo in 1995.1 But, as Gurr and Cole argue, it was not until 9/11 that the world finally crossed the threshold into the era of mass killing in which terrorists proved to be both willing and able to execute their plans.2 As Anat Kurz points out, the ‘9/11 attack itself, even though non-conventional weapons were not used, indicated that a threshold was crossed in terms of casualties and destruction, as well as in audacity and brazenness. This implied that a “logical” next step would be a non-conventional attack.’3 The 9/11 attacks were a shock, but they should not have come as a surprise. Islamic extremists had given plenty of warning that they meant to kill Americans indiscriminately and in large numbers.4
Although Osama bin Laden himself would not emerge as a major terrorist figure until the mid-to late-1990s, the threat of Islamist terrorism grew over the decade.5
