No one seriously thought Russia would invade Ukraine........
Quite the contrary. Putin and other Russian leaders have been extremely clear for many years that NATO overtures toward Ukraine were basically an act of war. The West caused this whole war. Russia sees Ukraine as part of Russia and NATO is not welcome. On the other hand, Finland is not seen as part of the Russian Empire and would be far less likely to be invaded.
The Biden regime wanted Russia to invade, foolishly thinking we could defeat the Russians either in a hot war or through sanctions.
Now, apparently the same thing is happening with Finland in order to provide justification for a hot war, which could set off WWIII.