Not only Ukraine, Russia is also hurting badly for new recruits. The people on the front for Russia come mostly from impoverished rural areas and they're running out of cannon fodder from the farms. Ukraine is racking up the body count, sometimes thousands per day.
After putin's last "reelection" he refused to expand his mobilization as he doesn't want to dip into the urban centers around St. Pete and Moscow. Putin is a maniac but he understands his support lies with his oligarchs and is centered mostly in urban areas. If he starts pulling people from the street in Moscow and St. Petersburg his support will errode and his power will be compromised.
Putin is a coward. He doesn't want to get pushed out a window himself so he needs to keep his rich patrons relatively happy. Conscripting the urban elite doesn't align with his strategy, risks compromising his support, and could ultimately lead to his downfall.
That said even the urban elite are growing suspicious of the regime. Drone attacks in your capital will do that to you. Some of his mercenary units have also started showing signs of discontent. Puttie is walking a thin line and is in desperate need of new recruits as the recent news from DPRK highlights. Hopefully this thin line leads to his death, very soon.
Then quarter (at least) of Americans are dumb as shit. Who's going to revolt? The low IQ boomer fuckwits that believe the shit they read on Facebook? Give me a break. Half of those wrinkly old shit stains are so glued to their own couches watching Fox "news" they'd probably have a heart attack from the physicality of walking up a steep incline.
So sick of this fucking bullshit line that we're going to have a civil war. Go the fuck outside and get some fresh air jesus christ.