Economically, the Russians have already hit rock bottom and is on the mend. However weak its economic power, Russia is a significant military power and will be for decades to come.
Whatever sanctions the U.S. can place on Russia, it would be impossible to topple the current Russian government as long as both Putin is in charge and China is there to bolster their economy. Russia will be able to source most daily merchandise that they need from China. They will still obtain enough revenue from selling weapons/natural resources to China. The idea of knocking out Russia when Putin and China are there is just a fantasy.
Ukraine, like Taiwan, had already seen its opinion shifted to the West, but as war clouds loomed, but no fighting, Ukraine will be facing economic disaster. No foreign capital will invest in Ukraine. All the young people are leaving for other lands, In a couple of decades, Ukraine will be shell of its former selves. However, it will not be able to determine its own fate, just as Taiwan will not be able to determine its own fate. It is decided by Russia and the U.S., to a much less extend, Europe and China, whatever the opinions of its population. Over time, if the economy of Ukraine does not get better, we may actually see the opinion of its population shift away from the U.S.
If Putin can hold out for a decade, the power shift to China plus the internal strife inside the U.S. will mean that the U.S. will increasingly be less likely to pick fights in that region.
I agree that there is benefit for the U.S. if a fight were to occur between Russia and Ukraine, but it is not about toppling Russia. The U.S. has found it increasingly difficult to challenge China and needs the Western Europeans to fall in line. A fight between Ukraine and Russia is just the thing to enforce such loyalties. However, we are powerless to provide any economic incentive to the Western Europeans, so we can only use the stick. In the longer run, this is unsustainable. After the pain of economic losses, Europe will eventually have to follow its own interests and away from the U.S. because we can only force Europe to take economic pain to stay with us on trumped up security issues. Putin is also playing well with his hand by scaring the heck out of the Ukrainian government so his does not have to actually go to war.
Actually, it seems Biden does not really want to go to war. If he did, he would sanction the heck out of the Russians. Once the sanctions are applied, there will be no more downside to the Russian invasion and the Russians might invade. Instead, he threaten to use the sanctions.
