I don't see it.

Russia has their hands full with Ukraine and has failed in the past to protect other allies such as Syria.

China seems wise enough to provide some support to Iran while sitting out of direct involvement in the war. China has everything to lose with war and nothing to gain. If anything, they are signaling "stability" to the Global South -- something from which the US is increasingly drifting away -- and war is the opposite of stability.

> Meanwhile, the US is still carrying out precision attacks with expensive ordnance which they have limited supplies of.

I think they have more than enough, plus Iran faces an even worse situation. Limited stockpiles of their only effective weapons, missiles and drones, and quickly running out. What's worse, by not using those weapons in huge salvoes, they reduce their efficiency... they only work if they can overcome defenses, but if they spend them too fast they lose their only effective weapon.

I think the Islamic Republic will be overthrown, but this requires boots on the ground, and it'll become a quagmire like Iraq or Afghanistan. At some point the US will declare success and leave, and from the ashes of Iran countless warring factions will emerge, an endless insurgency, and possibly the next ISIS. We've seen this happen more than once, no reason to believe this will go a different way.

Russia and China cannot stop this.

Edit: rather than downvotes, I prefer debate. Be better, HN. I realize this is difficult in times of war involving the country where the majority of HN hails from, but I trust you can do it. Engage in rational debate please.