The Iran-Iraq war was particularly bloody from the Iranian side, I recall. Human wave attacks sometimes involving Iranian children...
But, then again, the whole thing was pretty nasty: Saddam of course made heavy use of chemical weapons.
https://en.wikipedia.org/wiki/Iran%E2%80%93Iraq_War
Neither side distinguished themselves in battle. The Iranians used children to clear minefields. The Iranians were unable to mount any real offensive nor were the Iraqis. It was a war of attrition with both sides suffering substantial losses.
The Iranians would suffer the same fate as the Iraqis if they confronted the US.