As far as the left periphery is concerned, there is a conspiracy between syntax, semantics, and pragmatics to ensure the success of sentence formation. We would like to put forth the claim that peripheral features play an important role in this endeavor, which can be checked by either Merge or Move according to the parameter-settings of individual languages. Along this line, topic prominence can be regarded as the result of peripheral feature checking, and the null topic hypothesis à la Huang (1984) is reinvented as a null operator merger to fulfill interface economy in the left periphery. In this regard, Chinese provides substantial evidence from obligatory topicalization in outer affectives, evaluatives, and refutory wh-constructions, which applies only when the licensing from a D(efiniteness)-operator is blocked. The idea also extends naturally to the issues concerning pro-drop and bare nominals in general. In this light, we may well compare Chinese obligatory topicalization to those residual cases of verb-second (V2) in English, all being manifestation of the strong uniformity.