Deuteronomy 20 gives Israel instructions for warfare as the nation prepared to enter the Promised Land. The chapter addresses fear before battle, exemptions from military service, the organization of an army, and the treatment of enemy cities.
Its immediate setting is ancient Israel under the covenant God made with her. Still, the chapter raises enduring moral questions: What makes a war just? Is military power enough to secure a nation? What must be protected when a nation goes to war? And how should Christians understand biblical language about battle without confusing spiritual warfare with physical violence?
The first portion of the chapter gives two particularly important themes. Israel was not to be ruled by fear when facing a stronger enemy, and Israel was not to treat family life, productive work, and covenant faithfulness as expendable in the name of war.