June 1, 2012

Proliferation Security Initiative: Origins and Evolution

On December 9, 2002, the United States and Spanish navies cooperated to interdict a North Korean vessel, the So San, in the Arabian Sea.1 The operation initially appeared to be an unqualified success, a textbook example of interdiction to prevent proliferation of weapons of mass destruction (WMD), related materials, or delivery systems. According to press reports, the United States began tracking the vessel when it first left North Korea, believing that it was carrying a cargo related to Scud ballistic missiles. The So San flew no flag, making it a stateless vessel under international law, subject to interception and boarding by warships on the high seas.2 The United States asked the Spanish navy to stop and search the So San when the ship reached the patrol area of Combined Task Force (CTF) 150, then under Spanish command. The mission of CTF 150 was “to promote maritime security in order to counter terrorist acts and related illegal activities” in the Gulf of Aden, Gulf of Oman, Red Sea, and Indian Ocean.3 Thus, the United States proposed—and Spain agreed—to use a tool developed to combat global terrorism in a counterproliferation mission.