If you had diligently paid attention in middle and high school history classes, you'd know how critical "state formation" and "centralization" are—practically drilled into our heads.

Of course, textbooks generally only go so far as to say that once centralization takes hold and royal authority strengthens, everything falls into place nicely.

But if we dig a bit deeper, centralization and state formation are fundamentally connected to the presence of an "external threat."

As wars grow larger in scale, the power of a mere tribal chief or local lord becomes insufficient to manage them…

"Uniting around a king becomes the most …