'Abomination of Desolation'
Dan 11:31 "And forces shall be mustered by him, and they shall defile the sanctuary fortress (Jerusalem); then they shall take away the daily [sacrifices,] and place there the abomination of desolation."
Immediately after the Antichrist's 'Call to Jihad' for the hundreds of thousands of innocent Iranian civilians killed by the bombs and missiles from the US 5th Fleet, the whole world will be shocked by this massacre.
forces shall be mustered by him
For this great atrocity against humanity, non-Muslim nations (such as Russia, China, India, etc.) will likely fight alongside Iran. Muslim nations too will fight alongside the Antichrist.
Armies of king of the South
The king of the South comprised of Egypt and Israel. So when Egypt (supported by Saudi Arabia and the West) attacks Iran for the Nuclear and Missile programs, Israel will attack the nuclear sites.
There will be great confusions (just like God's enemies in OT) for the bombs and missiles from the US 5th Fleet killing so many Muslim civilians in Iran causing:-
1. Muslims in the Arab Sunni world to revolt against their leaders and hand their countries to Iran.
2. Muslims filled with hatred for Christians and the West to sabotage, revolt and rebel against the administrations, polices and militaries decapitating the Western powers or 'self destruct'.
The Antichrist with a powerful army but without any military resistance (Arab nations revolted and sided with Iran, and US and the West decapitated by internal revolts, sabotages, rebellions, etc.) will easily conquer Israel and Jerusalem (sanctuary fortress).
Luke 21:20-22 "But when you see Jerusalem surrounded by armies, then know that its desolation is near. Then let those who are in Judea flee to the mountains, let those who are in the midst of her depart, and let not those who are in the country enter her. For these are the days of vengeance, that all things which are written may be fulfilled."
After God has allowed the Muslims to take their revenge on the Israelites, Christians and abominable sodomites, He will send great earthquakes with huge tsunamis, diseases, plagues and pestilences, famines and hunger, etc. to punish the world and all the murderers until a quarter of man is killed.
Rev 6:6-7 When He opened the fourth seal, I heard the voice of the fourth living creature saying, "Come and see." So I looked, and behold, a pale horse. And the name of him who sat on it was Death, and Hades followed with him. And power was given to them over a fourth of the earth, to kill with sword, with hunger, with death, and by the beasts of the earth.
The great earthquakes and huge tsunamis will wipe out all food and fuel storages, factories, power station and grids, military bases, farmlands, etc. Without food and water all mankind will face extinction. Thank God for His great love for mankind that He, by miracles, will nourish His faithful servants and through them the whole world will be fed with food and His words and truth. This will be the greatest harvest and revival in the history of mankind.
Mat 24:6-8 "And you will hear of wars and rumors of wars. See that you are not troubled; for all these things must come to pass, but the end is not yet. For nation will rise against nation, and kingdom against kingdom. And there will be famines, pestilences, and earthquakes in various places. All these are the beginning of sorrows."