The war of Armageddon will be fought by Antichrist with his followers directly against Christ with His overcomers (Rev. 19:19, 11, 14; 17:14). Antichrist, the embodiment of Satan, will be the commander of Satan's army, and Christ, the embodiment of God, will be the Commander of God's army. Thus, on the one hand, it will be a devilish war; on the other hand, it will be a divine war. In this divine war, Christ will destroy Antichrist "by the breath of His mouth" and bring him to nothing "by the manifestation of His coming" (2 Thes. 2:8). These are the weapons Christ will use to defeat Antichrist.
This war will be the great winepress of the fury of God trodden by Christ at His coming back to judge the world (Rev. 14:17-20; Isa. 63:1-6). So many evil ones who hate God will join Antichrist in fighting against God. When these evil ones are gathered to Armageddon, they will actually be the grapes to be trodden by God in the winepress of the fury of His wrath. In bringing his armies and so many evil ones together, Antichrist will actually be doing a work for God.
The nations that will participate in that international war against Jerusalem will be gathered also by God. Half of the city of Jerusalem will be brought into captivity, but the rest of the people will not be cut off from the city (Zech. 14:2). In His mercy God will still preserve half of His elect people.
Jehovah will make Jerusalem a cup of reeling and a burdensome stone to all the besieging peoples, that is, to the armies of Antichrist and to all the evil ones with him. God will cause their horses to be bewildered and blind and their riders to be mad (12:2-4). Jerusalem will need divine protection not only against Antichrist and his armies but also against Satan and his demons and evil spirits. We may not know how God will make Jerusalem a cup of reeling and a burdensome stone, but we know that He will do this.