What you said, a joint pact between Iran and Russia with Russian millitary surrounding Iranian nuclear facilities, who dare attack them then. So, if Iran nuclear sites was to be taken out, now would be the time.
Or from Russias point of view, now would be the time to rush in and protect Iran from attack. Just conjecture. It is what I would do if I was Putin (thankfully I am not). Imagine the winter Olympics with Russia holding the entire Caucasus region and Iran their protectorate.
And we just denied Israel the means to do just that...