There was some confusion what exactly jus ad bellum and jus in bello were referring to.

To clarify the point, jus ad bellum includes the six principles used to decide whether or not a war is just. Jus in bello establishes the norms that govern the use of force in wartime.

I've already enumerated what jus ad bellum comprises, here is what jus in bello includes:

"1.) Discrimination: military force must be applied only against the political leadership and military forces of the state. Every effort must be made to discriminate between combatants and non-combatants, soliders and civilian, to minimize civilian casualties," says Mark Amstutz in International Ethics.

"2.) Proportionality: The destruction inflicted by military forces in war must be proportional to the goals they seek to realize. An indiscriminate war of attrition that seeks to eliminate the enemy society altogether is not morally justified," again says Mark Amstutz.

These are important to the conduct of war and the distinction between jus ad bellum and jus in bello will be elaborated upon--especially for the hard left--later.