actually they never do attack Border town, the girl at the end do try to assassinate him once when he leaves it at one point in the story however.
They don't realise what a threat he is because of something that happens to the investigators and focus their attention to the other 3 nations trying to take over the world.
and then the demons came
fun fact.
Depending on your point of view, the church is actually one of the good guys.
they are trying to save humanity by unifying it by force as they know the demons are coming to end humanity.