Our intelligence community knows plenty. Ever since his rebuke in 2014, Putin has been chafing to get Ukrainian access for convenient shipment of raw materials etc across Ukraine, but they gave him the (rightly so) middle finger. Our response to things like this (and other geo-political nastiness like Taiwan) has been gamed in the CIA and Pentagon think tanks over and over. The problem is obviously that we cannot not support a serious manpower-oriented play on the ground in Russia's backyard sandpile. There is a view by the way that any serious extension of heavy fire-fighting will only result in maximizing civilian deaths and destruction of Ukrainian infrastructure --- not my favorite vision of Ukraine's future.
I'd rather it be something like Finland with a secure cross-country transport system (employing Ukrainians) shipping Russian materials from Crimea and central Asia. These guys can't outcompete the US or Germany due to things like that; they just need it to become even a small serious player in world economy. Right now economists refer to them as essentially a big gas station of a country. ... and, by the way, the path to completely neutralize Russia is to completely embed them in the global economy, so that things like this become unthinkable for them. Despite the Nervous Nellie's, this is what has happened to China.
This current crap is about two things: a psychological issue with Putin and his self-image and political survival, and the Russian economy's need for easy and secure mass goods transport. And as for anyone thinking that nukes are in play, baloney. Making the place radioactive when you want to use it for massive goods transfer doesn't compute for anyone, even a semi-crazy one.
As to Russia's economy and China: China only represents 16% thereabouts of Russia's export buyers. If Germany, Italy, and the Netherlands begin shutting off their purchasing (this doesn't have to go to zero to really hurt the average Russian's lifestyle) China will not be interested in buying all the unsold stuff --- especially since Putin's bonehead play messes with overall world economics, which is really what China cares about. China has been known to us to have set global economic stability as the number one priority of their global view plan. They KNOW that they can outcompete everyone in stable conditions, even US on most things. They do not like meddling idiots, which Putin now overtly is.