It is the beginning of the 22nd Century since Christ. You're a committee of Angels and Archangels, brought together by God to give Her advice on a very important problem: the problem of War. While God's intentions cannot be questioned, his implementation of the species of homo sapiens has led to a precarious environmental situation on earth, in which the wars of the past 500 years have seriously degraded the quality of the environment on Earth, to the point that God fears that any further degradation would lead to the annihilation not only of homo sapiens but most other species of life on Earth. God wants to avoid this Cataclysm, and so has called you together to recommend three small things that God could change now in the makeup of Man, or of the Earth, or in other aspects of Her creation that would go the farthest in preventing future Wars. You have 30 days to give Her your holy recommendations.
Oh, (and this should go without saying), God wants you to base your recommendations on an actual assessment of the causes of War through the ages.
(Important Note: the above portrayal of the creation of Adam is not in conformity with the facts.)