Its harder. 20% of Russians(my estimate) have connections to Ukraine (relatives, friends, or were born there) and could be Ukrainian agents, there are lots of land routes how you can smuggle stuff. Things are not as well connected between Iran and US.

These people are used to executing civilians when they are the police. That's how IRGC, hamas and hezbollah work. You won't see much action from people like that when they can't just shoot anyone that they don't like.