If this wasn't terrorism, why did one of the men stand somewhat calmly and discuss what he did and why he did it to someone with a cellphone camera? People just committing a usual, run of the mill crime don't usually hold a press conference immediately afterwards.
As for the "War on Terrorism", I suppose western nations could deal with it like we did in the 80's and 90's and make it a law enforcement issue. Because the governments in the middle east always cooperate with western law enforcement.