Chechnya again, perhaps.
Putin will read through the Oswald-like operation. ISIS-K is the intended ‘target’.
FSB will note it’s a Mossad/CIA situation, via ISIS-K....pay-back for 7-Oct planning by Putin to get a halt to support going to the Ukraine by getting Israel into a ‘skirmish’.
If I were Putin, I’d find a way to help the Houthi folks, and plan in some way to sink a US Navy ship.
All of this drags us closer to a WW III adventure.
Only to point out here...in this Oswald-like adventure, if attacking the building was the true task...you’d just rig up some explosive pallet near the back, and blow up the building by remote control. It had to have the look and feel of a typical terror operation...in the most surveilled city in the world. If the Russians do have 4 gentlemen....I doubt that any of the four remember much of anything (like a Sirhan-Sirhan ‘game’).