People thought Russia would come in like the US went into Iraq, but that wasn't what happened. Russia invaded with a small force that was more akin to a peacekeeping invasion instead of that of an aggressor force.
The western countries had spent a lot to prop up Ukraine, they were just doing so in silent mode, because they didn't want anyone to know what they were really up to. When Donald Trump won the 2016 election, they had to go even further underground regarding the support they were providing to Ukraine, because he would have stopped that in its tracks.
This also blows a gigantic hole in your contention that Putin wants to reconstitute the USSR. If Ukraine would stop the hostilities in eastern Ukraine & promise to not join NATO, Russia would leave the remained of Ukraine intact. Had they followed through the peace agreement back then, they most likely would have retained Ukraine in its original configuration, with perhaps the exception of the Crimea.
Russia lies all the time
if you haven’t figured that out by now, you’re not very smart