I mean, sure, but also blackbody radiation. And much more of that.

What’s the town? You can’t just promise a bounty of food and not name-drop it.

Iroh is not a pacifist. He is just very selective about the use of deadly force.

Iroh tries to teach zuko how to kill his enemies unflinchingly with “cold-blooded” lightning, and when that fails, teaches zuko to redirect lightning, which he knows is — and makes clear to be —explicitly deadly force, “to turn your enemy’s energy against them”. He acknowledges that, if he were to defeat Ozai, it would be “brother killing a brother”, because there was no realistic world in which Ozai could be contained without leading to his death. He accepts that his granddaughter “is crazy and needs to go down”.

When he chooses to take back Ba Sing Se, does he go in covertly and retake the puppet state from the occupying troops by forcing a surrender or a diplomatic solution? No, his opening move is to generate the largest ball of fire possible, then hurl it at the titanic wall, which not only does the camera show us has many people behind it, but which Iroh is ready to obliterate, soldiers and all, sight unseen. He does what must be done. Violence is his last resort, but he clearly has no moral compunction against using violence against the violent. Deadly force is met with a redirecting blow, carrying that same energy or more. In the first season, when he believes the fate of the world hangs in the balance, he threatens and uses deadly force “tenfold” that which is exacted upon the moon spirit. There is nowhere in the show that Iroh says that death is never the solution. The only reason we don’t see the deaths of the many soldiers occupying Ba Sing Se at Iroh’s hands (as well as all of the other times he has caused soldiers to be buried under their own boulders, breathed fire into their faces, or otherwise used violent infernos to defeat enemies) is that it was depicted in a kids’ show. The only person in the series who maintains that deadly force is never the answer is Aang. Aang only manages it in the finale by Deus Ex Machina because he’s the chosen one (and the protagonist of a kids’ show).

He wouldn’t word it that way, and he wouldn’t suggest that killing is universally the best way to go about it, but this is not the least likely thing that could come out of his mouth, as another commenter pointed out “Azula is crazy, and needs to go down”. Even as he turned down the team’s request to defeat Ozai, he made it clear that it could only end in death, “brother killing brother”. He was under no illusion that capturing Ozai was ever an option.

Do you think that the white lotus took back Ba Sing Se without killing anyone with those 100-foot-tall walls of fire? No, you don’t expel an occupying force by just cutting the tips off of some spears. Avatar shows us the least-bloody parts of the recapture, but do not mistake Iroh’s depiction in a kids’ series for pacifism. Iroh is very clear, vocally, that violence is necessary in some cases. He teaches zuko to redirect lightning to send it back at the person who launched it, as he says “to use your opponent’s energy against them”. He prefers nonlethal methods, but that doesn’t mean he refuses to employ deadly force. He and his friends use heavy fire against enemy metal tanks, which would boil alive the soldiers inside. They use rocks to stop up the holes through which benders were actively shooting fire, which would rebound and fill the tank with that same conflagration. Those tanks get shot up hundreds of feet in the air and have hard landings on top of one another, which would not only concuss anyone inside to death, but would crush all of the tanks on the bottom. Iroh literally starts the liberation of Ba Sing Se with a fire blast large enough to completely obliterate the titanic wall, as well as everyone previously depicted positioned directly behind it, in an instant. He doesn’t know how many soldiers lie behind that wall. He just destroys it, sight-unseen.

Iroh is not a pacifist, he is just very selective in his use of deadly force.