Reading Fire and Blood got me realising a lot of time George R R Martin will have a character lose a war because other characters do extremely contrived or stupid things purely because the event is needed to ensure a result.

I.E Despite years of Ironborn preferring to plunder the westerlands for its riches, such as Dalton Greyjoy. Balon Greyjoy decides to attack the north because otherwise Robb Stark would likely have never started to lose the war and he would need Tywin to have done something clever to beat Robb.

Another example is in Fire and Blood when Rhaenrya has kings landing and all seems to be going well for her. Suddenly Hugh and Ulf betray her at Tumbleton and it’s even said no one understands why, on this Eustace, Munkin and Mushroom all agree. It’s the battle of tumbleton that ultimately causes her to lose kings landing, flee to dragon stone and die.

If Balon never attacks the north and does the smart thing and raids the westerlands. It’s likely Robb never loses the North and wins the war. If Hugh and Ulf never betray Rhaenrya and instead do the smart thing and carry on fighting for her with superior numbers, it’s likely she wins the war.

For all of his really good worldbuilding I have just noticed that he does like to create tragedy by contrivances