Gen. Mark Milley Speaks At 100th ROTC Anniversary

Army Times
by Michelle Tan

“If the world if 1916 was complex, or the world of 1945 was complex, the world of 2016 is intensely complex, and I can tell you that from personal experience,” he said. “You’ll be dealing with terrorists, you’ll be dealing with hybrid armies, you’ll be dealing with little green men, you’ll be dealing with tribes, you’re going to be dealing with it all, and you’re going to be dealing with it simultaneously.”
-Mark Milley

Was he trying to be humorous...What the heck does little green men and hybrid armies mean?

http://www.armytimes.com/story/military/careers/army/2016/04/22/army-chief-leaders-winning-everything-combat/83395612/?from=global&sessionKey=&autologin=