It doesn't support a procedurally generated world like you are asking but there was a game for Sega CD called Third World War that I loved to play that had a good balance of diplomacy, trade, and war.

https://en.wikipedia.org/wiki/The_Third_World_War_(video_gam...

There's a Paradox game I played a few years ago called Supreme Ruler that I got excited about thinking it was similar but it tends to get bogged down in the military in my opinion.

https://en.wikipedia.org/wiki/The_Third_World_War_(video_gam...

I haven't played Victoria II but know it also fits this mold. It is set in the colonial time frame so not quite modern but close.

https://en.wikipedia.org/wiki/Victoria_II