This article was originally published by TruthoutVaya aquí para la versión española.

The wars of the last century have offered important lessons for peace.  Among these are:

Wars begin in the minds of men (and women) and are often based on the lies of leaders.

Wars can occur when they are not at all expected.

Politicians and generals send the young to fight and die.

Wars can consume entire generations of youth.

Wars are not heroic; they are bloody and terrifying.

Wars now kill more civilians than combatants.

Long-distance killing and drones make wars far less personal.

Any war today carries the risk of a nuclear conflagration and omnicide (the death of all).

The terms of peace after a war can plant seeds of peace or the seeds of the next war.

The best ways to prevent illegal war are nonviolent struggle and holding leaders accountable for the Nuremberg crimes: crimes against peace (aggressive war); war crimes; and crimes against humanity.

Lessons offered unfortunately do not necessarily translate into lessons learned.  Philosophers have warned that we must learn the lessons of the past if we are going to apply them to the present and change the future. In a nuclear-armed world, the challenge is made all the more urgent.  As Einstein warned, “The unleashed power of the atom has changed everything save our modes of thinking and thus we drift toward unparalleled catastrophe.”  Today, learning these lessons for peace and changing our modes of thinking to put them into practice are necessary to assure that there is a future.

David Krieger is President of the Nuclear Age Peace Foundation.