What does Zechariah 12:6 mean?

On that day, I’ll make the leaders of Judah like a blazing fire in a pile of wood, like a torch in a field of dry grass. They’ll burn up all the nations around them, but Jerusalem itself will stay safe. Zechariah 12:6 - Modern Text Bible

(God will make Judah’s leaders powerful and unstoppable, defeating their enemies while keeping Jerusalem secure.)