"I'd have to look it up but the usual suspects are borders and trade and, like, sociological conflicts of various subtypes."

...those seem like terrible reasons to have a war even when you can get everyone back afterwards.

"Usually for assorted reasons there are not clear alternatives or the decisionmakers aren't well-incentivized or both."

I'm so sorry. 

I thought that the hands-off creators would be a good thing but, wow, that doesn't sound worth it at all...ugh...I do not know how to solve wars unless you have not invented the concept you should talk things over calmly and not kill people.

"It's been invented."

Then yeah. I don't know. 

Probably we should try to find someone whose powers do involve going between worlds and then the Valar can have a look and see if they can resurrect you and if not - well, I don't know, but with more people working on it it'd be easier to end wars.

"I'm a little concerned that it'd be easy for underinformed third parties to do more harm than good."

It would really surprise me if they did more harm than wars but perhaps they could explain their proposals to both sides first so that anyone could raise any objections to the effect that more harm would result than resulted from the war.

"I guess. Wars often arise in or create really delicate political situations, and sometimes attempts to squish delicate political situations lead to more problems down the line in non-obvious ways, like, 'stop fighting over this land, here, we'll draw this line and enforce it as a border, whoops, that line wasn't repsonsive to where all the representatives of the cultures involved were and now there are neighbors who don't get along and same-culture members who can't easily interact' kind of thing."

...you could, like, Lórien it so everyone can go there but no violence can be done there and you won't see people you don't want to see? But I am not a person who does politics and I have not thought about this sort of problem for very long.

"Don't know what Lórien is."

Lórien is the home of the Vala of dreams, and also a name that people use for him, and the land changes to be whatever suits you at the moment and it arranges that stressful things not come about. 

It's boring. But it much improves on wars and if you go there with people who aren't boring then it won't be.

"Sounds nice, I guess."

It's not terribly boring, it will do bubble baths and springy trees and bizarrely flavored flowers.

"I don't normally rely on the landscape to provide my entertainment."

Ah. We travel frequently.

"Do you guys want to come home with us, this place is scenic but I'm starting to feel the lack of chairs."

Sure, if that's convenient for you.

"I can only take one non-sister passenger at once, who's first?"

Twins shrug. One of them steps forward.

And now he's in the living room of a house in Phoenix.

He blinks. He blinks more. 

"Welcome!" And she goes back and gets her sister and his brother.

Politely blinking Elves!