Heh, probably 15. Hmmmm. What's needed, I guess, at least for WesWorld II, is a way to separate available income from domestic production. Some countries, like modern Saudi Arabia for example, have lots of available income (at least when the oil market's high), but little domestic production capacity. They can buy weapons on the world market, but have little capability to make them at home. If Persia's oil resources are developed, then they'd be in the same boat: a fair amount of money, but domestic production is out, at least for a while.
Some conversion to the WW factory system could be possible: say an equivalent of 1,000 tons of income converts to 0.05 IP (half the IPs normally generated by domestic factories). That way, a resource-rich country could, if it WANTED to, boot-strap itself up, but it would be a long-term process and one that's more expensive than just buying things outright overseas.