Simcity has online where you can trade with other online players for products. You can even get into sort of trade alliances with other cities. Been a while since I last played it though so not sure how it is now.

SimCompanies may be what you're looking for.

Bonus if there's an online combat aspect or something close.

I'm currently playing township.   But im looking for something where you can import/export goods from other players?  Maybe trade routes?

[REQUEST] city builder with economics/trade with online players?