Commentators explain that when Satan (the dragon) failed to prevent Christ's ultimate victory, he didn't give up; he changed his strategy. His location changed, but as Charles Spurgeon notes, his hateful nature did not. Scholars see this verse as a shift from the failed pagan persecutions to more insidious attacks from within the church, such as widespread heresy (like Arianism) or corrupt religious systems. This shows Satan's persistent opposition to God's people.