Jehovah will strike all of them who besiege Jerusalem during the war of Armageddon. Their flesh will rot while they are standing on their feet; their eyes will rot in their sockets; and their tongue will rot in their mouth. A great panic from Jehovah will be among them; and each will seize his neighbor's hand, and his hand will rise up against his neighbor's hand. Furthermore, the wealth of all the surrounding nations will be gathered together, gold and silver and garments in great abundance. The same plague will be on the horse, the mule, the camel, the donkey, and all the cattle that are in those camps (14:12-15).
Jehovah of hosts will be the strength of the inhabitants of Jerusalem and will make the leaders of Judah like a fire pot under wood and like a torch of fire among sheaves, and they will consume all the surrounding peoples on the right and on the left. Jerusalem will dwell again in her own place. Jehovah will save the tents of Judah first and then the house of David and Jerusalem. In that day Jehovah will defend the inhabitants of Jerusalem, making the feeble among them like David and the house of David like God, like the Angel of Jehovah (Christ) before them. (In 12:8 the Angel of Jehovah is in apposition to God.) Moreover, Jehovah will seek to destroy all the nations that come against Jerusalem (12:5-9).
Zechariah 14:3-7 reveals that Jehovah as Christ will then come with His saints and go forth to fight against Satan, embodied in Antichrist, and his followers, the nations.
The feet of Jehovah as Christ will stand in that day on the Mount of Olives, which is before Jerusalem on the east. The Mount of Olives will be split at its middle toward the east and toward the west into a very great valley so that half of the mountain will remove to the north and half of it to the south (v. 4).
The remnant of Israel will flee into the valley of Jehovah's mountains (v. 5).
In that day there will be no light; the shining ones (the sun, the moon, and the stars) will withdraw. It will be a kind of day known only to Jehovah, neither day nor night. But at evening time there will be light (vv. 6-7). This indicates that God will change many things in the universe in order to judge the evil human beings and to save His elect.