Ukraine has excellent farmland. Russia has their own local economy and can produce most of the things they need just with their direct neighbors. French cheeses, American-branded phones, and Italian cars may be too expensive for the Russian economy, but the Russian government doesn't care. Close-enough products can be had for a fraction of the price.

Thinking of things in terms of raw GDP is what is getting the west into a total mess. For years now people have said Russia won't do anything and couldn't possibly be a threat because their GDP is so low. China will never be a major player because their GDP per capita is so low.

But that's, frankly, stupid. People in Switzerland pay $20 for a sandwich. People in Vietnam are paying $0.75 for a sandwich that tastes twice as good. People in China are getting locally made phones with the equivalent of US pocket change and riding high speed trains for the cost of a slow and janky NY subway trip. GDP means absolutely nothing outside of international trade within the global sphere. GDP didn't help America beat Afghanistan, one of the absolute poorest countries on earth. It didn't help them beat North Korea or Vietnam either. They still haven't succeeded in removing communism from poverty-stricken, bottom of the barrel GDP Cuba. If Russia decides to keep moving into western Europe, their GDPs mean nothing. Seizing that land just means Russia gets all of what those countries have, forever, without the high price tag.

GDP isn't motivating angry dictators to invade. They're doing it because they can.