The time of war that starts with the opening of the second seal is brought about by the kingdom of darkness for a specific purpose. It’s a crisis of their own making that they will provide the fix for. The man of sin will perform supernatural signs and wonders that will cause the wars to cease. He declares himself to be God and the deceived masses follow him. He then proceeds with his plan to rid the world of those who refuse to worship him.
And he deceives those who dwell on the earth because of the signs which it was given him to perform in the presence of the beast, telling those who dwell on the earth to make an image to the beast who had the wound of the sword and has come to life. And it was given to him to give breath to the image of the beast, so that the image of the beast would even speak and cause as many as do not worship the image of the beast to be killed. Revelation 13:14-15 NASB
People must either worship the image of the beast or be killed. The image of the beast is essentially a code of conduct that the deceived people of the world agree on that affirms the man of sin as God. He will breathe life into it by enacting it as law. People must worship it by obeying its mandates and those who refuse to do so will be killed. This time of martyrdom is what takes place when the fifth seal is opened.
When the Lamb broke the fifth seal, I saw underneath the altar the souls of those who had been slain because of the word of God, and because of the testimony which they had maintained; and they cried out with a loud voice, saying, “How long, O Lord, holy and true, will You refrain from judging and avenging our blood on those who dwell on the earth?” And there was given to each of them a white robe; and they were told that they should rest for a little while longer, until the number of their fellow servants and their brethren who were to be killed even as they had been, would be completed also. Revelation 6:9-11 NASB
The man of sin will gain control of the world’s economies and require that everyone receive his mark in order to buy or sell anything. This is an aspect of the image that will expedite its implementation. It will force people into quickly declaring their allegiance either for him or against him.
And he causes all, the small and the great, and the rich and the poor, and the free men and the slaves, to be given a mark on their right hand or on their forehead, and he provides that no one will be able to buy or to sell, except the one who has the mark, either the name of the beast or the number of his name. Revelation 13:16-17 NASB
There will be no neutral ground. Everyone must decide whether they are going to save their lives by receiving his mark and worshiping the image, or reject him and be killed.
Then they will deliver you to tribulation, and will kill you, and you will be hated by all nations because of My name. At that time many will fall away and will betray one another and hate one another. Matthew 24:9-10 NASB
This passage in Matthew summarizes the time of martyrdom. When faced with the life or death ultimatum of the image, many will fall away and save their own lives by worshiping the man of sin. Those who remain true to Jesus will be persecuted and killed.