Russia and China have been sending military aid to Iran. China has also cut the US off from rare earths supplies which is affecting American military production. Clearly that hasn't been a sufficient deterrent though.
And there's really nothing that can be done in terms of international law because the US simply ignores it.
Obviously neither Russia nor China want to have a direct military confrontation with the US either. That would be WW3, and likely lead to a nuclear holocaust.
So, it seems like a war on Iran is unavoidable at this point.