Only if you haven't been paying attention or have the "war to end all wars" delusion that people sometimes seem to get. There have been all kinds of wars going on in Europe all the time basically forever[1].
Europe's history is full of this, but yes no joke there were many, many political observers who, not too long after the conflicts in the Balkan countries in the late 90s, and as countries formerly under Soviet influence became liberal democracies felt that this era of European history was in the past, that liberal democracies wouldn't invade one another yada yada and that there would never be any more wars in Europe.
Obviously they were wrong, or perhaps there just needed to be an asterisk next to Russia as they quickly regressed away from becoming a liberal democracy and all the conflicts recently have involved Russian aggression against its neighbours.
Are you talking about the 2022 invasion? The 2014 invasion? The Yugoslav wars in 1990? The cold war? The world war? The other world war? And that's just living memory.
How unthinkable is something that last happened between the same two countries eight years prior ._.
