As he listened this far, Simon tilted his head. The demon Lords suddenly started expanding territories? The reason sounded too flimsy and whimsical for it to invoke a war of such a massive scale.
As a demon noble himself, he knew that the territory in the Demon continent wasn't favourable to life which is why the fertile land of the central continent was so coveted.
However, the demon noble had overcome that by establishing their own dungeons. As long as they had enough DP, they could turn their place into any place they found desirable.
There was no meaning in the demon nobles aggressively expanding their territories other than as a show of force. However, even then it was not feasible to risk full on war with the Alliance.
Even he who was not born in this era, could see that. So there is no way the other high ranking demon nobles weren't aware of it either.