Progressive war[1] is a military strategy in which only enemy combatants are targeted, and non-combatants killed or wounded by collateral damage are kept to a minimum.
Its principles were established by Dutch jurist Hugo Grotius, who is considered to be a founder of international law, in his book De jure belli ac pacis libri tres ("On the Law of War and Peace: Three Books"), published in 1625.
A successful practitioner was Helmuth von Moltke the Elder, as chief of staff of the Prussian Army in the 19th century.
Unlimited war uses military action against civilians, in the hope of undermining the will to fight by the people and their leaders so that they end their resistance.
Many consider it a form of terrorism in the sense of deliberately attacking noncombatants in the hope of changing their mindset.