I noticed when starting a game in the Modern/Transhuman Era that Missile units don't require any resources to build. I think there should be some resource requirement for high-tech units, so I'm going to add a couple (you can only have 2 requirements, one AND and one OR, per unit, but the OR becomes an AND if you give it only one choice).
- Missile: Requires Oil Products.
- Cruise Missile: Requires Oil Products and Aluminum.
- Smart Missile: Requires Oil Products and Semiconductors.