Strategic Notes on Third Generation Gangs builds upon the third generation street gang (3Gen Gang) theory first articulated in a series of papers by John P. Sullivan in 1997. From that foundation, Dr. Sullivan and Dr. Robert J. Bunker, editors of this volume, and others have expanded that core to articulate the threat that sophisticated gangs with transnational reach and political dimensions pose to community, national, and global security. This Small Wars Journal-El Centro Anthology provides empirical depth to their theoretical perspective, bringing together strategic notes and essays on third generation gangs and military-trained gang members with new content assessing the theoretical and policy ramifications of both theory and reality on the ground. — Dave Dilegge, SWJ Editor-in-Chief