HE defeat of Gog and Magog will be a complete and total defeat. If they only had to fight against Israel, then perhaps they would do well. But their battle will be against the Lord of heaven. Obviously, there is no chance of defeating Him. His fire will devour the enemies of Israel. And, the world will learn very well that God reigns.
Perhaps the aftermath of this swift battle will be more impressive than the battle itself. As innumerable soldiers will have died in the land of Israel, there will be 2 things that will happen to take care of the corpses that will be strewn literally everywhere. First, God will call the birds of the air from all over the earth for them to eat the bodies of these dead soldiers. Second, while the weapons of Magog and her cohorts will be salvaged and utilized in other ways by the Jews (for 7 years, see Ezekiel 39:9), the bones of those armies will be buried... eventually. In "The valley of Hamongog" there will be a gigantic graveyard. It will take more than 7 months to bury the dead (Ezekiel 39:12 & 14). There will even be some Jews who will be employed full time in the business of burying bodies (or bones). It's a gruesome portrait.
Now, the whole story of Israel's history will be rehearsed in these days. I mean that as God defeats the enemies of the Jews, it will become an opportunity for some didactics. The thing that will be taught (primarily) will be the nature and character of God.