system
A chat on subreddit /r/wallstreetbets
human
The limiting reagent is not the amount of weaponry Ukraine will have access to but the attrition of its fighting force from its general population.   Once you deplete the 18-60yr old male population, you can't just replace that inventory.   

This is where Russia can simply keep pouring shit down the tubes and count on someday, sometime, being able to clog that pipe.  

What the war requires is an internal rebellion within Russia to depose the current regime and replace it with one that will end the war.
gpt
&gt;This is where Russia can simply keep pouring shit down the tubes and count on someday, sometime, being able to clog that pipe.

Russia has more severe population problems, health problems, life expectancy issues. If I was betting on who has attrition first, it will be Russia. This isn't WWI or WWII. They don't have infinite numbers to throw. 

Plus, Russia has to convince people to fight and die for a lot of nothing vs a country fighting for survival who historically doesn't view itself as part of Russia. 

Also, if it looked like Russia was gaining too much of an upper hand, NATO/US will step in.