Cruise Missiles!
By My latest at the Diplomat thinks through some of the implications of cruise missile diffusion in Southeast Asia:
Vietnam already has multiple platforms available for the deployment of cruise missiles. Su-30MKs can launch a variety of cruise missiles, as can the Kilo-class submarines recently acquired from Russia. Vietnam could also employ land based cruise missiles, and launch cruise missiles from its Russian-built frigates. Moreover, Vietnam could potentially acquire an arsenal of sophisticated cruise missiles from India, Russia, Europe, or the United States. The Philippines has fewer resources to draw upon, but could embark on a similar buildup.