If Russian forces can quickly sweep through Ukraine and take control of the country in a week or two with minimal fighting, Putin will emerge from this as a big winner. But if Ukraine forces put up fierce resistance and drag out the battle for control of the country into the spring, then this may be the beginning of the end for Putin. The Russian stock market lost about a third of its value overnight with some banks losing up to 60% of their value. The Ruble has also crashed and is trading at all time lows. Russia has positioned itself with enough foreign reserves to be able to withstand this initial blow, but those foreign reserves are also crashing as world markets take a beating.
Whether Ukraine forces are willing and able to stand up to Russia is the big question. Zelensky was ironically an anti-war candidate when he ran for election but has since given in to pressure from the militant nationalists to take a harder line with Russian and make moves back towards NATO. Most people in Ukraine aren't particularly fond of their government as it is still rife with corruption and control by Ukraine oligarchs. So, it is a big "if" as to whether the military is going to fight to the end or give up quickly to cut a deal to coup Zelensky and transition to a Russian republic.
The other question is whether Russian forces are up to a bloody battle. This is virtually a civil war with Russian forces fighting friends and neighbors. This is not like the Chechen war where Russia was fighting Muslim separatists who has ties to terror groups. This is more analogous to US forces invading Toronto that US forces invading Iraq. The Russian military is well equipped and has a battle hardened air force. But the average Russian conscript has no battlefield experience and is usually poorly paid and treated like dirt by commanders and officers. If Russia follows the Chechnya play book (bombing the country back to the stone age), it may spare ground forces significant combat. But it may also unite the world (save and except for China) in basically expelling Russia from the world economy. Thus, anything short of a fast and relatively painless invasion is going to be a huge problem for Russia.
Finally, I think this invasion has nothing to do with the current US administration. Putin did this because he needed something to unite the country. Russians generally like Putin because he delivered the country from very bleak economic times under Yeltsin's corrupt government. But the strong GDP growth Russia saw in the early 2000s is long gone and Russia's dependence on oil markets has meant a crash in 2015 when the Saudi's flooded the market and tepid growth that collapsed once the pandemic hit. Putin has no economic agenda that can lift Russia out of its economic turmoil and had to turn to a wartime economy to distract Russians from the fact that the country has been ravaged by the pandemic and has little prospects for better economic times in the future. So, if this conflict drags out and Russia suffers an economic collapse as a result, Putin may not be in power by the end of the summer.
