Consider Phlebas said the Culture and the Idiran first came into conflict in 1267. the reason for the war was that the Culture and the Idiran had dominant ideological aims that were inherently incompatible with each other, that being the case I would have thought they were inherently "in conflict"?

the Culture felt that Idiran expansion was going to threatened the Contact section's ability to improve life throughout the galaxy, and the Idiran state religion said they had to keep expanding no matter what. Even if no shots had been fired, the inevitability of conflict and war must have been apparent to any (non eccentric) Mind living in 1216?