It may seem simplistic, but definitions are important in war. William C. Martel frequently stressed this. Goals and objectives, the enemy, and victory must all be defined in order to bring clarity of thought to operational planning and public messaging.

In an era when mass-casualty human conflict was primarily characterized by war between nation-states, this was relatively easy to do. Destroy the military, take the capital, or subdue the population, and victory came in a neat little package known as "surrender."

But it has gotten more difficult as interaction capacity has increased across the globe due to modern cyberspace, open borders, and low trade barriers. Combined with the destructive capacity that can be wielded by small non-state groups because of the potency of a range of potential weapons, armed conflict is harder to label in distinct categories than it used to be. It has become more fluid and less constrained to specific spaces, although geography still matters a lot.

Photo Credit: U.S. Army photo by Spc. William Marlow/Released