Okay, so not looking at all of the obvious wrongs that Sylvanas committed during Shadowlands and by killing Saurfang. I’m going to say it was justified to start the fourth war against the Alliance. Okay so this is before Shadowlands and so without knowing Sylvanas’s true intention was not to advance the glory of the Horde. The Horde was, in my opinion, justified in starting war with the Alliance, for the following reasons:
- The Alliance are evil and stole the Amani trolls land, then imprisoned Talanji and Zul in the Stormwind stockades. This is evidenced in the quest to free Talanji from underneath Stormwind, called Stormwind Extraction.
- The Alliance are a supremacist and elitist faction, evidenced by how they treat the Blood Elves (when Kael’thas was leader) and Amani trolls (during both the Troll wars and the Second war) and the Orcs (internment camps lasted way longer than internment).
- Gilneas will not stop terrorizing the Forsaken, in the Silverpine forest they are sacrificing their own people to kill Forsaken.
- The Horde would be better off without the Alliance for the reasons above.
I think this is important to make the distinction between Sylvanas being wrong in allying with Zovaal and Sylvanas being justified in starting the fourth war. Both can be true. The Alliance like to blame the Horde for starting the fourth war and then lump all of Sylvanas’s actions together and blame the Horde for all of them. But to be clear, Sylvanas was only wrong after killing Saurfang and leaving the Horde and Forsaken.