The start of WW3 is not today, it is not this year or next. The Chinese, Russians, North Koreans, and Iranians all felt the power of three B-2 bombers and six bunker busters.

Did any get shot down? Were they even spotted? If Iran never saw it coming, then the Russians, Chinese, and everyone else will be in the dark. How do you fight an enemy that cannot be seen? You bend over and take it… If they do get involved, then they could be next, and then what do they do when we bomb them?

Attack a few American land bases and wait for extreme retaliation? It’s very simple: we can definitely hit them at home, and they can’t hit us in North America… where does that put them in the fight? Better they do not get involved and save some face.

The Russians and Chinese are very close on turning on each other and would rather that fight then get humiliating destroyed by the Americans. Fact is they only pretend to be allies when it suits them.
TLDR:
Not Russia.
Our top priority is keeping the US from helping Ukraine. Antagonizing Trump by screwing him in Iran is the last thing we need right now.
LONGER ANSWER:
The reaction of our Foreign Office as per the afternoon of June 22 is very indicative. The newsfeed on their front page at mid.ru is as dull as a diplomat’s necktie. No dramatic splashes in the “Foreign Ministry statement in connection with the US strikes on Iran”.
Between the lines
In the text, the Americans mentioned in connection to the “strikes on several nuclear facilities.” Also, there are words about “confrontational and destabilizing actions taken by the United States and Israel.” Apart from that, the words about “this reckless decision,” “aggression,” and suchlike hang without particular attribution.
We’re not happy about what you guys do, but we won’t call you names.
No drama
“This has drastically increased the likelihood of a larger conflict in the Middle East, a region already plagued by numerous crises.”
We don’t want to blow it up larger than it is. The Middle East is forever Middle East.
Don’t look at us
“We expect the IAEA leadership to respond promptly… the UN Security Council must take a firm stance as well.”
Iran, you can’t win this
“We call for an immediate end to aggression and for stepping up efforts to bring the situation back onto a peaceful, diplomatic track.”
If you can’t shoot back, don’t expect us to do that for you.