http://foreignpolicy.com/2015/03/04/the_future_of_war_adios_clausewitz/?wp_login_redirect=0
Article by Justin Lynch

“War therefore is an act of violence to compel our opponent to fulfill our will.” - Carl Von Clausewitz
In a white, perfectly circular rotunda at the Reagan International Trade Center, military officials and foreign policy experts gathered at the New America/ASU Future of War Conference. They sat at perfectly circular white tables, ate from perfectly circular white plates, and tried to create a perfectly precise definition of war. Yet the age of Clausewitz is over, a panel found. No longer is war only an act of physical violence, as Clausewitz theorized. In the future, what defines an act of war will become increasingly non-violent.
The norm of what constitutes war is changing said Charles Dunlap, a retired Air Force JAG general, “especially when you move over into the cyber realm”. For instance, if there were a cyber attack on a country where nobody was killed, but caused the stock market to crash, could that be considered an act of war? Under the classic definition offered by Clausewitz, it wouldn’t be. Nobody was physically harmed. “I think the norm is evolving” Dunlap said.
So where can we draw the line of what constitutes a war, asked Rosa Brooks, a Schwartz fellow at New America. Does that mean that economic sanctions can be considered an act of war? What about psychological tactics? Almost anything could be attributed to an act of war, it seems.
“Where I think the line drawing could happen is the element of control over other people.” said Naz Modirzadeh, the Founding Director of the Program on International Law and Armed Conflict at Harvard Law School “The law on armed conflict is about when you control other people.”
And while in the future, the definition of what is a war will change, who is fighting in that war will also change. The rise of cyber-warriors will see a similar rise in the number of contractors tasked with these roles, said Laura Dickinson, a Future of War Fellow at New America. Can “they be considered to be directly participating in hostilities?” she asked. “If they are, it changes the calculus over whether they can be targeted changes.”
“Some of those people might not realize it, but they are belligerents, they are targetable, and they are targetable in the same basis as active duty military” said Dunlap.
That means that if the United States were to change its strategy in Syria and suddenly start fighting Assad, contractors in the United States could become legal targets.
Throughout the entire conference, a recurring theme was the asymmetric nature of war. We won’t know how, or who the next target will be. It could be a company like Sony. And bear in mind, these rules only apply to state actors. So if the definition of war is ever evolving, who is considered a combatant in war is expanding, and the targets of war are becoming more diverse, does that mean we are in a constant state of war?