Regarding warships, customary rules on innocent passage and freedom of navigation codified in the UNCLOS are far from being settled among State Parties. FONOPs impose the US understanding of rules on passage and navigation in each and every sea area, forcefully implementing deregulation in order for the US to create a navyfriendly environment for its worldwide mission. By implementing another agenda of carrying out the new US policy of “Pivot to Asia,” the FONOPs in the South China Sea challenge the very heart of China’s sovereignty, and may bring about adverse effect to the process of peaceful settlement of territorial issues and maritime disputes in the South China Sea region. China believes the US FONOPs in the South China Sea are offensive to its sovereignty. Moreover, their adverse effect to the process of peaceful settlement of territorial issues and maritime disputes in the South China Sea region cannot be ignored.

The USS Lassen’s October 2015 South China Sea freedom of navigation operation was exemplary in some respects and cautionary in others. This article argues the Lassen’s mission to sail within 12 nautical miles of one of China’s artificial islands was a successful albeit exploratory challenge because the operation has helped to clarify maritime claims in the region and garnered international support for continued operations. This paper examines the US Freedom of Navigation Program’s broader goals of benefiting the international community with a rules-based system. It also argues that increased transparency is essential if these goals are to be achieved. This article analyzes China’s unclarified claims in the South China Sea and explores the concept of “psycho-legal boundaries” in relation to the so-called nine-dash line. It concludes by presenting suggestions for plotting a proper path forward for FONOPs in the region with an emphasis on protecting the marine environment.