The arguments are right out of cold war history (interesting in a way calling it “history” when it was such a part of my real life for so long).
First; war is inevitable because of the basic conflicts between the two alliances
NATO vs Warsaw Pact/China becomes Horde vs Alliance
“I believe the exiles of Gilneas will never forgive the Horde for driving them away. I believe the living humans of Lordaeron think it is blasphemy that my people still hold their city. I believe the ancient divide between our allies in Silvermoon and their kin in Darnassus is not easily mended.”
“I believe the Darkspear tribe hasn’t forgotten who drove them from their islands,” she continued. “I believe every orc your age remembers being imprisoned for years in filthy camps, wallowing in despair and surviving on human scraps. I believe every human remembers the tales of the terrible Horde that caused so much destruction in its first invasion, and I believe they blame every orc for that, no matter what your people have done to redeem yourselves. And I remember very well that I and my first Forsaken were once loyal Alliance citizens. We died for that banner, and our reward was to be hunted as vermin. I believe that there will be no permanent peace with the Alliance—not unless we win it on the battlefield on our terms. And believing that, answer this, Saurfang: what use is delaying the inevitable?”
Then the assumption that the new weapons could wipe out both sides effectively ending civilization, coupled with the assumption that an Alliance first strike means an Alliance victory and an end to the Horde:
What if the Hord holds off and the Alliance strikes first?
“You are the only living creature I know who has conquered both Stormwind and Orgrimmar, Saurfang. You say a direct attack on Stormwind is impossible with our forces today. Is the same true for the Alliance? Do we have enough natural defenses in Orgrimmar to repel a surprise assault?”
“Then the Horde charges into battle and dies honorably that day, because there will be nothing else left for us but a slow death inside these walls.”
Azurite weapons subbing for fusion weapons for the MAD scenario
“ … Azurite sightings are coming in from across the world, Saurfang. We still do not know its full potential, nor does the Alliance. We only know that it will create a new generation of warfare. What will war look like in twenty years? In a hundred?”
“And by all the spirits, Sylvanas was right, no matter how strongly Saurfang tried to deny it. War would come again one day, and if both factions were strong, that war would raze entire nations. How many different peoples on Azeroth would become extinct in that fight?”
“If a hundred years of peace ends with a war that annihilates both sides, it was not a worthy goal.”
So to summarize:
The choices are; Alliance strikes first without the nukes, Horde is defeated, Horde strikes first and the divide and conquer strategy succeeds, Alliance is defeated, maintain the piece until both sides have nukes, both sides annihilated unless the prospect of annihilation itself restrains all factions.
The MAD scenario is, in fact, Saurfang’s only counter to Sylvanas’ logic, he agrees with all her assessments, but his idea of honor and his PTSD convince him that it is more honorable to risk the MAD scenario.
Whoever is writing this stuff may see Saurfang as the “good guy” because in real life it has become popular to believe that the MAD strategy worked in the real world, we haven’t had a nuclear war after all, but as written I have to agree with Sylvanas’ logic.
Real world predigest often translates into in game role play.