Revelation 8:2-6

2 And I saw the seven angels which stood before God; and to them were given seven trumpets.

3 And another angel came and stood at the altar, having a golden censer; and there was given unto him much incense, that he should offer it with the prayers of all saints upon the golden altar which was before the throne.

4 And the smoke of the incense, which came with the prayers of the saints, ascended up before God out of the angel's hand.

5 And the angel took the censer, and filled it with fire of the altar, and cast it into the earth: and there were voices, and thunderings, and lightnings, and an earthquake.

6 And the seven angels which had the seven trumpets prepared themselves to sound.

The seven angels that are now standing before God may be the same seven angels that were in the right hand of Jesus that had oversight over the seven churches on earth. These seven angels of the churches may be given the power to carry out the wrath of the Lamb on those that persecuted the Church on earth (spoken of at the fifth seal). The prayers of the saints are about to be answered and Jesus will judge those on earth who persecute and kill His saints.

The wrath of the Lamb does not come without reason. It comes in answer to a specific time of persecution of saints on the earth. When each angel blows the trumpet given to him, a specific judgment will fall upon the earth. These judgments do not come as a result of the warfare of man as did the horsemen of the seals. These judgments come because Jesus is angry and He answers the prayers from the saints for justice. Before the judgments come, the passage indicates that the prayers of the saints ascended up before God. An angel then took the censer containing the prayers of the saints, filled it with fire and cast it upon the earth. The voices, thunderings, lightnings and the earthquake indicate that judgment has been summoned from the throne and angelic forces are being told to prepare for action. 

Some prophecy writers make all the judgments in Revelation come as a result of man's own weapons and a result of his own wars, but this chapter makes it pretty clear that what is coming is pay back time to those who dwell on earth who have the blood of the saints on their hands. The first five trumpet judgments have nothing at all to do with any war caused by man.