U.S. Homeland Security Secretary John Kelly speaks during an appearance with Mexican Interior Secretary Miguel Angel Osorio Chong in Mexico City, July 7, 2017 (AP photo by Eduardo Verdugo).

It has been more than 14 years since the U.S. military last fought large formations of conventional enemy troops. Unless the unthinkable happens with North Korea, American forces may not see a large-scale traditional war for many more years to come, if ever. Yet, every day, the military, intelligence community, law enforcement and other government agencies face a plethora of shadow enemies, ranging from complex criminal-terrorist networks to ideologically motivated individuals. While the risk of conventional war or gray-zone aggression from an adversary state is not gone entirely, the 21st-century security environment is dominated by nonstate challenges. This is an […]