Islamic State claims responsibility for London subway attack that injured 29; terror threat ‘critical’
“This was an attack on London’s transportation infrastructure, and it doesn’t seem to be an opportunity attack — someone had the time to gather resources and build the device,” said Erroll Southers, director of USC’s Homegrown Violent Extremism Studies program.
“Trains are open and a vulnerable system. It is a soft target. It is likely to encourage more copycat attacks, and it’s also going to require an extraordinary level of security to deter these things from happening.”