system
Given the following post, respond as if you're commenting on Reddit:
human
[LOTR]Are all orcs inherently evil , warmongering and violent? Or could there be some peaceful night ones who would oppose the war and prefer to cooperate with other races?
gpt
In Letter 153, Tolkien states that Orcs aren't irredeemably evil. 

> They would be Morgoth's greatest Sins, abuses of his highest privilege, and would be creatures begotten of Sin, and naturally bad. (I nearly wrote 'irredeemably bad'; but that would be going too far. Because by accepting or tolerating their making — necessary to their actual existence — even Orcs would become part of the World, which is God's and ultimately good.)

So are Orcs evil? Yes. Could they be changed? Possibly. Has one ever been changed? Not that we know of.

As far as we know, all Orcs are violent and warmongering. They're beings made of corruption, so all of the "good" has been effectively corrupted out of them. They can still show positive traits, e.g. Ugluk was brave and had good leadership skills, but Orcs will entirely use these "good" traits to do evil.

If they're not fighting Men, Elves or Dwarves, they'll fight among themselves. And they'll only ever deal with other races under extreme circumstances. Worth noting that after Sauron's final defeat, Orcs either killed themselves or fled to deep, dark places. None of them surrendered to Aragorn's army.