I think it's pretty obvious that Vulcan has some pretty imperialistic foreign policies.
Think about it. Archer and all these other Humans resent Vulcans for "holding us back," and apparently interfered to keep Henry Archer from being able to test his Warp 5 Engine design (established in "Broken Bow"). The Vulcan Ambassador is constantly allowed in on internal United Earth Starfleet functions, including the hearing on the actions of Archer whilst in the Delphic Expanse.
The implication is pretty obvious: That the United Earth government has basically been deferring to Vulcan's wishes whenever the Vulcan government decided it didn't like something Humans were doing. The relationship seems akin to that between the United States and, say, one of the five thousand banana republics the U.S. government installed in Latin America in the 20th Century: Nominally independent, but bowing to the will of a stronger nation any time that stronger nation wants it.
The implication seems to be confirmed by what we see of other Vulcan relationships. We know that the Vulcans and Andorians seem to be involved in a sort of cold war. We know from "Shadows of P'Jem" that Vulcan is propping up the Coridanite government even as it faces a civil war (with the rebels being supported by Andoria). Meanwhile, we know from "Fallen Hero" that Vulcan was also in the business of helping one faction of Mazaarites depose another faction (through the justification that this other faction consisted of a "cabal of criminals").
To me, it looks like Vulcan engages in "soft imperialism" -- finding less technologically-developed worlds and moving in to control their development while the natives are still awed that there are actual aliens, until they have a local government in place that always or almost always does whatever Vulcan wants when there's a conflict.