"The PSI is in substance a form of export control regime activities between and among major allies of the Unites States, which belongs to the typical supply-side approach in terms of the proliferation management. In short, the PSI is not possibly a new paradigm for the proliferation management, contrary to the expectation of some wishful thinking group in field of non- proliferation. In this respect, any effective strategy for nonproliferation must also involve demand-side measures. This paper consists of three sections: the first section looks into the nature of the PSI in terms of political, legal and military dimensions. It begins by assessing the policy change with its center of gravity from 'nonproliferation' to 'counterproliferation.'Based on this assessment, the paper in the second section explores what the PSI can do in the course of conducting nonproliferation efforts and what not by comparing two 'interdiction' cases of the So San and the BBC China. The third and concluding section deals with an alternative suggestions how the future strategy for proliferation management should be pursued policy-wise."