So because things are complex and the Iranians weren't reduced to puppets, the Russians have to give the Iranians weapons to send to Iraq to kill Americans? Not buying it.
They know what's going on in Iran. It is the leading terrorist organization in the world and has been since Jimmy Carter handed it to the Islamists. I don't care how "complex" things are. Iran supports terrorists and the killing of Americans by terrorists. Iran supports the defeat of American in Iraq. By arming Iran, the Russians also support those goals. That's not complicated.
The great nuance and complexity of a situation is a BS excuse used by liberals, the State Dept. and, apparently, Russians when they want to do something they know is wrong or will get them in trouble if they do it directly.
Far from being "complex", Russian foreign policy in Iran is straightforward. It has always liked to have an "insane-little-brother" countries. It uses the insane-little-brothers to accomplish geopolitical goals that Russia cannot accomplish directly. Then periodically, it will pretend to restrain the insane-little-brother to extract concessions from the current target of the insanity.
Currently, Russia is using the Iranians to defeat the US in Iraq.
So Russia is happy to deal with Islamic terrorists as long as they play the role of insane-little-brother. The Iranian regime obviously has no problem with the insane part.
Today it is pretty much a Chinese client-state, but the Russians are making a major effort to get as much influence as they can in the place.
That's not necessarily bad.
As far as Iranians using Russian weapons to kill our guys, "W" has it in his power to remove Iran from the face of the Earth and put a stop to that. I would, in fact, encourage him to do so on the slightest pretext.