Borders in Southeast Asia are largely insecure boundaries that were established by colonial administrations to stabilized spheres of influence or mark internal administrative divisions. They were not designed to withstand international pressures. Sovereignty was not defined in a strict territorial sense. And local rulers used marginal territorial concessions as policy instruments. Thus no boundaries in Southeast Asia are "hard" in the Western sense. General mobility across them continues largely unimpeded. Consequently, the process of eliminating enemy sanctuaries requires an effective administrative presence, not just military action. In Vietnam, border policymakers must also consider international repercussions arising from boundary policy options. The conclusion of this examination of SEA border problems is that the manner in which boundary surveillance is exercised and control technology applied will be critical to the stability of the region.