Okay...it's not cool for people to keep moving the article back and forth.  We should agree on a single solution before anyone moves forward with any major action.  I am personally for the "Fourth International (United Secretariat)" title because, while I am generally (not officially) a supporter of the FI, I recognize that there is some historical ambiguity, and am seriously interested in the neutrality question here on Wikipedia.  When you mention the FI, you are invariably asked "which one?"  And the truth is that "United Secretariat" will always answer the question.  I feel that it's different from titling the article "United Secretariat of the Fourth International," which is misleading, as that's the now-defunct body that directed the FI for 40 years.  We're disambiguating, because "Fourth International" is touchy ground for Trotskyists outside of the FI (you know which one).  "Reunified Fourth International" isn't used by anybody.  "Fourth International (1963)" posits a 1963 founding that didn't really happen.  "Fourth International (United Secretariat)" is also parallel to Fourth International (ICR), where the organization identifies itself as "The Fourth International" but the article uses a no-longer-present body to disambiguate it.  Any move at this point is going to be, in some respect, not entirely neutral in its point of view.  Given that reality, I think that recognizing convention and using the United Secretariat, while clearly explaining the nomenclature issues up front in the article, remains the best way to present the FI as it has been since 1963.