The treaty did seem to prevent an all-out war very efficiently - even the Minos Korva thing was heavily dependent on the Cardassians believing it would not result in a war.
As for joining totalitarian alliances, the Feds really shouldn't be the ones to speak. Or perhaps you were indeed referring to their longstanding alliance with the Klingons, and their instigating the war with the Dominion?
It would be interesting to learn what sort of treaties the Feds signed with the Klingons. Supposedly, the end of the Cold War with them led to the discontinuation of a Neutral Zone rather than the erection of one. Were there technology limitation talks? Territorial exchanges? Defining of spheres of influence?