Saddam was paid (in chemical weapons, but not only) by the US to invade Iran, it didn't work well for them at the time, despite the MEK helping them with hidden routes and a lot of local support they don't have anymore. The current Iraki leadership isn't stable enough to do the same anyway.

Afghanistan and Pakistan are in a small war that will have some impact on Baluchistan, but official Pakistani ground troops are a no-no, because it will leave ground for the Taliban. Also India invested a lot in Baluchistan biggest port, and Pakistan threatening their investments will probably have them react (India love nothing more than helping Pakistan adversaries). Koweït is too small, Irak Kurds need to secure their autonomous region, and US promised are worth basically nothing. Azerbaijan used Iranian drones and artillery against Armenia like 2 years ago (maybe 3), and Iran apologised publicly after sending a missile to them.

All of this to say: only the US have the manpower and will for a ground invasion.