It's 1942 and I have no rubber, my MILs are not replacing my Sturmoviks shot down by the German AA and I can't even afford to build Katyushas for my RP. I spend half a year doing "control trade" mission on Siam and get a pitiful 12 rubber for 2 civ factories. Historically the USSR produced 110,000 aircraft (and received another 15,000 through lendlease), I can't produce even close to these numbers because of rubber shortage.