At this point general mobilization would be a disaster regardless the stated cause. The economy is already suffering due to worker shortages. Russia is doing everything in its power to get bodies from almost anywhere else (a new group of North Koreans are on the way). Even if he fully mobilized, this wave of new troops can't be adequately armed. Russian armor in virtually non-existent. The few T-90's in production are being culled as soon as they appear on the battlefield.It would also surely give Putin the chance to drape himself in the flag and extend the draft to the rest of the population. An attack on Russia/ Russian interests would be an attack on Putin, and vice versa. My real concern is that if Trump is baited into even the focused use of force like we saw with Iran, Putin has the excuse he needs. And I doubt he is not above defending his interests with nuclear weapons when he is losing.
Defending one's interests with nukes is defense via national suicide. Whatever Russia attempted to do the the West would be visited upon them many fold. Whether Putin fully understands this or not, his military leadership does.