Arise, O LORD! Let not man prevail; let the nations be judged before you! Put them in fear, O LORD! Let the nations know that they are but men! Selah
God's sovereign rule puts everything in its place, including the actions of all the people in the world. Not even the smallest legislative fine print, nor the worst atrocity of war escapes His awareness and action. The world of humanity is answerable to God.
David's experience was that at times it seemed like evil men were prevailing. This is a personal knowledge and also his perspective as a ruler of men. His enemies were winning over him... and thus this confident cry for God to move so man did not prevail. The nations are not autonomous. Everyone is judged by God. And all people who do evil must one day answer in fear before God. When God judges us, we are reminded that we are not Him! We are only men.
My experience in nearly a half century of living on this earth is that God is greater than the world of men. But honestly, sometimes it does not seem that He is showing it. There are evil actions all over the planet that seem to go unchecked. There are atrocities and vile abuses of helpless people. And it hurts to know this. Especially since it violates both human conscience as well as God's Law.
But the thing to do is not to question God's wisdom or ways. It is instead to appeal for Him to take action among us... even through us. Sometimes the way that the nations are judged is through God's use of other people to get their attention. Assyria invaded faithless Israel in judgment. Babylon humbled Judah back to repentance. People are used by God to show His sovereign rule. Yet, even then, we are only men.