On 17 September, two explosions occurred in Seaside Park, New Jersey and in the Chelsea neighbourhood of New York city. The two detonations were the result of a pressure cooker and pipe bomb placed by Ahmad Rahami, an Al Qaeda sympathiser arrested by police two days later following a shootout in Linden, NJ. Twenty-nine people were injured in the explosion in downtown Manhattan. Also on 17 September, a man identified as Dahir Adan was shot dead by an off-duty police officer in the Crossroads Center Mall in St Cloud, MN, after he stabbed ten people. The stabbing is believed to be unconnected to the New York and New Jersey bombings, and it is unclear whether Adan, who is believed to have asked some of his victims if they were Muslim, held any significant Islamist sympathies or connections with terrorist organisations. None of the three attacks caused any fatalities.
The attacks have heightened public anxiety as to the potential risks that lone actors, either motivated by extremist beliefs or by mental illness, pose towards public safety. Even relatively crude attacks, such as those that utilise bladed weaponry or improvised explosive devices (IEDs), can undermine the public’s confidence in the ability of highly capable US counter-terrorism authorities to interdict terror plots in the face of the increased overall jihadist threat. In addition, such attacks highlight the effectiveness of efforts by terrorist organisations such as the Islamic State (IS) and Al Qaeda to encourage followers through persistent propaganda campaigns to carry out attacks in Western countries. The aforementioned incidents reflect similar incidents that occurred in Germany and France during the summer period, including the axe assault on train passengers in Wurzburg, Germany, the mass shooting in the Olympia Einkaufszentrum shopping centre in Munich which killed ten people, and the bombing attack outside a wine bar in Ansbach, Germany.
These trends suggest that US and European cities are likely to experience an increase in low-scale terrorist incidents carried out by lone actors in the long term, as the Islamic State continues to encourage its supporters to attack those who support military operations against the organisation in Iraq and Syria. Further assaults may also be prompted by the ‘copycat’ phenomenon, in which individuals seek to emulate the level of media attention and infamy which surrounds the perpetrators of previous terror attacks. Assaults in Europe are likely to focus on transport hubs, large retailers or malls, leisure areas and city centres. In addition, limited security capabilities make suburban or rural areas vulnerable.