“the whole purpose of NATO was to prevent war with Russia, or was it?”
Yes, and you don’t prevent wars with an aggressor like Russia by appeasing them.
Now that is done, the war will be over quickly, Putin will have his win to crow about for local consumption and the EU will have a sence russia is back on a back foot.
Russia has a previously undefended and wide open boarder to defend, with actual trained professional solider class on the other side, and not just cousin Sergey. That is going to hurt in Year over Year costs.
This is why a war with Ukraine was always the dumb, it screeches russian air defences across areas where NATO can go deep and cause major issues if something get spicy to the south.
Semantics.