The world’s militaries—and especially the most advanced military in the world, that of the United States—are now caught in the vortex of technological change.

“God is on the side of the big battalions.” The historical record is opaque about whether it was Napoleon, Turenne, Voltaire, or indeed any identifiable Frenchman who made that statement, but, in this age of supposedly post-industrial warfare, He has apparently changed His mind. Equipped with an iPhone and GPS-guided munitions, God has broken the phalanx, emptied the battlefield, and super-empowered the individual. Mass—particularly the large military formations of the modern era: infantry divisions and corps, aircraft carrier battle groups, tactical air wings—has gone out of style.

Retired Marine Gen. James Mattis is a legend among Marines, and he’s credited much of his success on the battlefield to reading. Now, thanks to a recent interview with History Net, we know what’s at the top of his reading list.

Tucked into the surveillance bill that became law was a little-noticed section that will let the United States complete ratification of two long-stalled treaties aimed at stopping a frightening scenario: terrorists wielding radioactive bombs.