The current threat environment facing U.S. forces across the globe is so extensive that Gen. Dan Caine, the chairman of the Joint Chiefs of Staff, does not believe that even famous spy novelist Tom Clancy would have been able to envision them before his death more than a decade ago.

“Tom Clancy, on his most inspired day, would probably struggle to come up with the number of serious and simultaneous events that are going on in the world right now,” Caine said Wednesday during the Billington Cybersecurity Conference.