The ultimate motive of Satan is to deceive Christians (he was successful with Adam and Eve) to believe heresies thereby disobeying God's words and commandments causing them to lose their salvation and be cast into Hades. Any deception of others is eventually used to deceive Christians and the remnant Israelites.
Rev 6:7-8 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.
Since God is fighting against Israel and the West (esp. US) for their many abominations, it will be easy for Iran (led by the Antichrist) and allies to annihilate the powerful military might of the West. However, when Israel and the West is conquered, God ensured that only those destined to Hades (including depraved and covetous Christians) are killed. Thank God that godly Christians are preserved by Him during WW3 where 1/4 of mankind will be killed (almost 2 billions - more than the population of the continents of Americas and Europe).
Mat 12:25-26 But Jesus knew their thoughts, and said to them: “Every kingdom divided against itself is brought to desolation, and every city or house divided against itself will not stand. If Satan casts out Satan, he is divided against himself. How then will his kingdom stand?"
In order that the Antichrist can form the powerful 'One World Order' to replace the present ineffective and abominable UN, God will allow the Antichrist to use all his Satanic powers to deceive Muslims to come under his control.
Muslims worldwide Deceived
Luke 21:24 "And they will fall by the edge of the sword, and be led away captive into all nations. And Jerusalem will be trampled by Gentiles until the times of the Gentiles are fulfilled."_
After the Antichrist had conquered Israel and Jerusalem, he will declare that Allah used him to conquer Jerusalem for the Muslim. Immediately, the majority of Muslims will be deceived to accept this demonic Antichrist as a prophet of God. Deceived Muslims in the West will immediately rebel, sabotage or fight against their adopted countries by civil wars, setting off bombs, causing electric outages, fires, damages, murders, etc. resulting to millions being killed. These rebellions and sabotages will bring great fears and hopelessness to the West, bringing them to their knees.
One World Order
Rev 17:12 “The ten horns which you saw are ten kings who have received no kingdom as yet, but they receive authority for one hour as kings with the beast."
When the war is over, the Antichrist will then be declared as the 12th Imam, the saviour of Islam, Head of the 'One World Order' and Ruler of the world.
However, during this time of great sufferings of mankind from great starvation, plagues, diseases and pestilences, caused by wars, earthquakes and huge tsunamis, destroying all foodstuff, the love of godly Christians feeding them with divine provision (just like manna), care and healing them in Jesus name will see the majority of mankind find salvation.