The word nexus, with origins from the Latin word for -to bind, - signifies a connection, tie, or link. Since the mid-1990s, nexus has been used to describe various connections, ties, or linkages between terrorist and criminal trafficking groups, but these relationships have been a topic of increasing national and international security interest since the terrorist attacks of 11 September 2001. Separately, both terrorists and traffickers have concerned law enforcement, security personnel, and policymakers for decades. However, the notion that the different types of criminal organizations...