I don't see how I can trade strategic resources. They don't seem to be an option on the bargaining table. I see the luxury resources listed there, but no strategic resources. I've gathered from the guidebook that I should be able to trade these. How do I do it, or is there some reason these are not listed as a trading option? I need to know PDQ cuz I only have one source of saltpeter, and Japan, China and France have all declared war on me (they had a mutual protection pact)!