If you want to parse the differences, I would say that an "enemy" is someone who we're basically at war with, while a "foe" is competition that we simply must beat.

There are any number of terrorist organizations that are our enemies. At this present time, that's the list.

Trading partners are not foes. They are partners. There may direct competitors on individual deals or for specific resources where there is a definite win-or-lose thing going on, but in the big picture everyone is either a partner or nothing at all.

For fucks sake. There are no cultural foes. Period. It is neither a war nor a competition.