The Trigger Of War is a sidequest in Star Ocean: The Divine Force that can be picked up at Castle Aucerius.
You can find Bertrand at Castle Aucerius inside one of the rooms.
He wants you to head to the Terranus to take out 30 Vey'l soldiers that are hiding out there.
You'll need to go to the Terranus and scour the whole ship to take out all 30. They don't respawn, so you'll need to go room by room to make sure you clear them all out.
Don't forget to use the Elevator to head to the lower deck as you can easily miss this area.
Once you have wiped out all 30, head back to Bertrand for your reward.
- 30,000 Fol