Excerpt from Just War Dominion by James Brown Jr.:
"Who is this King of glory? The LORD strong and mighty, the LORD mighty in battle." - Psalm 24:8
The Bible describes Jehovah as a man of war. While this should begin to shape our worldview that war is not inherently evil, many never begin by defining the nature of war. Johannes Althusius wrote in Politica, "War is therefore a general state of strife, and a proceeding in which two conflicting peoples who submit to no common magistrate settle their controversy by force and arms"
"A noise shall come even to the ends of the earth; for the LORD hath a controversy with the nations, he will plead with all flesh; he will give them that are wicked to the sword, saith the LORD." - Jeremiah 25:31
War is the settling of controversy between nations. War establishes righteousness or evil. However, it is important to understand that war is not essentially evil or a necessary evil. The Bible says in Exodus 15:3, "The LORD is a man of war: the LORD is his name." To say that war is evil in its essence is to say that God is evil even though God does work all things for good (Romans 8:28).