Even the biased Dalish storyteller thinks the Dalish probably played a part in their downfall.
That doesn't mean they attacked first or that the events played out the way the humans claim they did.
Also, the "biased" (oh right, like Andrastian historians scholars - who are all clerics by the way - aren't biased) Dalish storyteller also points out that human version of that part of history was written from the point-of-view of the winners.
Tensions between Orlais and Dales strain due to Dales not helping in Second Blight
And humans finding elves creepy for living in their own country and practicing their own religion.
Quoth the Daish Codex from human POV: "But the old era wasn't through with the[ elves]. In their forest city, the elves turned again to worship their silent, ancient gods. They became increasingly isolationist, posting Emerald Knights who guarded their borders with jealousy, rebuking all efforts at trade or civilized discourse. Dark rumors spread in the lands that bordered the Dales, whispers of humans captured and sacrificed to elven gods."
It wasn't just the second Blight, humans also couldn't stand elves living in their own country, minding their own business, not wanting to be bothered as well as not bothering others, preferring to worship their own Gods instead of converting to the one the humans felt they should worship instead.
Chantry sends missionaries to Dales to spread Chant
Even though the elves didn't ask for and didn't want them there.
Dales kick missionaries out
Which the elves were well within their rights to do since it was their country and their religion, and they could refuse the Chant if they didn't want it.
Imagine if the elves had sent missionaries trying to convert humans to their religion, humans told them to GTO, then elves sent their Emerald Knights to try to force the humans to keep their unwanted missionaries within their borders to convert their people?
Chantry sends Templars to defend missionaries
Why would they need to "defend" the missionaries if the elves were just kicking them out? Unless they were just trying to keep them from getting kicked out, which sounds an awful lot like forcing their religion on the Dales to me. If the elves don't want them there, they don't have to keep them there. The missionaries and Templars should have taken the hint and kindly left, not tried to force the elves to let them stay in.
Dales butcher the town of Red Crossing then start carving through Orlais
According to the humans, the elves started the war by butchering Red Crossing. They claim the attack was unprovoked and the village completely defenseless (and imply it was the first attack), but I'm not sure. Considering humans had already been poisoning people's views of elves by "rumoring" of human kidnappings and sacrifices to elven gods (with no proof), provoking the elves by trying to push their way into their borders, push their religion onto them, then sent armed Templars in response to the elves throwing the missionaries out, I rather doubt it. It sounds like humans attacked first, and/or there was already fighting and/or there was already war by the attack on Red Crossing and/or the carving through Orlais. (Toward the Andrastian capital where most of the Templars are, after Templars had been sent into elven territory.)
Before the war, it was humans who consistently wanted into elven territory and not the other way around. After the war, it was humans who got ownership of the elven territory they had wanted into before. Just saying.
Orlais asks for help which the Chantry gives in an Exalted March
Against the elves that rejected their missionaries, then fought against the Templars they sent in response to the elves rejecting their missionaries.
Dales forces pushed back into the Dales and have the ability to make war stripped from them
If they made war in the first place at all. More like "have the ability to reject Anstrastianism [as a nation] stripped away from them."
I say again, just because the humans claimed x, y, and z happened doesn't mean their version is automatically the correct one.