Andoria and Vulcan have been at odds for two centuries by the time ENT begins; the Vulcans have been in contact with Earth, but not sharing technology, for one century.
Denobulans and Antarans ended their war 300 years prior to ENT.
Organians have a noninterference policy and intend to make first contact with humans in another 5000 years or so.
The Coalition of Planets is a forerunner organization to the UFP, consisiting of Coridanites, Vulcans, Humans, Denobulans, Rigellians, and Andorians. The UFP is founded with 18 members.