1 Corinthians 15:52 In a moment, in the twinkling of an eye, at the last trump: for the trumpet shall sound, and the dead shall be raised incorruptible, and we shall be changed.
Revelation 8:1-2 When he opened the seventh seal, there was silence in heaven for about half an hour. And I saw the seven angels who stand before God, and seven trumpets were given to them.
Numbers 10:9 When you go into battle in your own land against an enemy who is oppressing you, sound a blast on the trumpets. Then you will be remembered by the Lord your God and rescued from your enemies.
The war has been started by the nonbelievers.