Ukraine

Yes if the war ended tomorrow, I suppose you are right they could rebuild some of what they've lost, and become stronger than they became at their weakest.
But it would be very dangerous politically to allocate a lot of ressources to the military after the war, when the country is in dire need of restoration to where they were before the war. Even if they haven't been bombed much, Russia has lost a lot economically, investments in infrastructure and production has been near zero for almost 2 years already, even the already existing capacity hasn't been maintained.

Russians a getting poorer fast, and just ending the war will not automatically turn things around, the economy is not healthy, and Russia needs to allocate ressources for restoring the economy, which will mean that ordinary household economies will be strained for years.

The "magic" economic growth we saw after WW2 will not happen for Russia, because the conditions that existed back then to create it, are not present today. For instance women entering the workplace in greater numbers. Where Russia will remain short on manpower.