Simple attacks by grassroots jihadists have become a fact of life in the West. Indeed, we saw three such incidents on Sept. 15: the bombing attempt against a subway train in London , a knife attack against a French soldier at a Paris subway station and a hammer attack against two women in Chalon-sur-Saone, France. These incidents are among the latest in a long string of incidents across the globe that featured attackers armed with simple weapons such as knives, vehicles and crude bombs. Our tactical analysis team has provided advice to our Threat Lens clients to help executive protection teams adjust to this new reality, but in light of recent events, I think it would be useful to provide some guidance to help people protect themselves from such attacks.