Some of you are saying that neither the Dalesmen nor the elves would come to some sort of peace treaty with the drow of House Jaelre, but aren't giving any concrete reasons other then "but they're drow!" or "they aren't trustworthy".
Everyday (in the current FR timeline), people in the Dales and the Cormanthor die because of the drow. If the Dalesmen or the elves had any real way of solving this problem, they would have by now. The Dalesmen aren't organized well enough and have never been. The elves are too few in number. Yet, they both loose people every day.
If the drow of House Jaelre approach these groups with peace treaties that would stop the killing and the raids, you think they'll turn them down out of hand? The Dales aren't run by paladins (as per the DMG, most people are neutral, not good), normal people run them. People who want to live in peace and prosper more then they want to point moral fingers. Is it somehow better to keep things as they are? Let the deaths continue? How does that help anyone? It just doesn't make any sense to me.
I wish to understand the basic argument being made.
Because the elves and the Dalesmen fear that the drow will betray the peace treaty and get back to killing and raiding, they won't agree to a peace treaty, so they want the drow to continue as they are now, killing and raiding?
Right now they have the very thing they fear, why would they wish to continue it? It just doesn't make any sense to me; perhaps I'm missing something.
Let's assume that House Jaelre will only do this to gain an advantage (why does anyone ever agree to any kind of treaty, if not to gain an advantage?). Won't the Dalesmen and the elves use the peacetime to gain just as much of an advantage (or even more, as some posters have implied)? All sides must know that any treaty is for each group's advantage, and each group will do just that... take advantage on it. The drow will strengthen their defensive positions, the Dalesmen will train more arms men, and the elves will shore up their borders. Everyone uses the time to their advantage... as everyone knew they would. If House Jaelre attacks, then the elves and the Dalesmen are ready for them (and probably more unified due to the treaty). If House Jaelre does not attack, then all the better for everyone involved. There is only benefit to all the groups involved, regardless of future attacks.
I'd also like to add some other issues to this:
1) House Jaelre and worshipers of Vhaerun drow are unlike any other drow. You can't use the same ideas of behavior on them as you do for other drow. They want to form permanent surface communities. They want to reunite with their surface elven kin, standing together as a whole. This even goes as far as intermarrying with the other elves (which is encouraged). They actively hunt Lolth worshipers, something that would work well with the elves and the Dalesmen. Lastly, their main goal is simply to survive. So, I think the assumption of them wanting to crush everyone else for their own goals does not fit House Jaelre, their very goals show that.
2) The Dalesmen (and less so the elves) won't actually be very knowledgeable at all of drow behavior and traits. They'll know a very basic reputation from old and very varied tales on the drow. They'll know them much more as aggressive raiders, not as traitors (what deals have the drow broken with any of them in the last millennia?). It's not like they've had any experience with them beyond they being simple aggressors.
3) People keep mentioning that trust is required for a treaty... why? Show me a single treaty in our history, between two warring nations, that's based on trust. Historically, most peace treaties aren't about trust, since neither nation trusts each other (if they had, they wouldn't have gone to war). Peace tends to be brokered over the needs of each group and how it can help the other, be it people (you might want to stop loosing them in battle), food, gold, etc. If a group has no resources to offer, peace isn't needed since that group lacks the resources to actually wage a long-term war. The leader of each of these groups has to decide what's best for their people. Sure, you might not trust the drow, but their constant attacks aren't exactly helping you.