Guns n' Roses once asked, "What's so civil about war anyway?" 2 Samuel doesn't have an answer to that question—but it provides numerous examples of civil war and rebellion. These wars are about unifying the people of Israel and Jordan under one king—but they're also, in a way, God's wars.
Samuel makes this pretty clear with its whole sequence about the capture of the Ark: these wars aren't just wars between people, they're wars between deities. And in 2 Samuel, the fact that Absalom's plans are supposedly scattered by God—who defeats Ahithophel's counsel with Hushai's—helps bring home this point, as David does when he insists on dedicating all of his plunder to God.
Questions About Warfare
What is the purpose of David's wars? Is the underlying motive religious or material or both? What is God's motive in supporting and, in a sense, leading these wars?
Does 2 Samuel have an implicit anti-war message at any point? What about in David's song lamenting the death of Jonathan and Saul?
How does Saul's persecution of the Gibeonites differ from the massacre of the Amalekites in 1 Samuel? Is there a significant difference?
What does it say about God since he cares about the welfare of the Gibeonites? Does this concern for another people demonstrate something new about the nature of God?