To understand the drivers - and the limitations - of the evolving and historic Vietnam-US military relationship, the strategic port of Cam Ranh Bay is a good place to start.
The Washington-Hanoi relationship is coming under even closer scrutiny this weekend as regional security chiefs and analysts meet in Singapore for the informal Shangri-La Dialogue.
When US Defence Secretary Leon Panetta leaves Singapore, he heads straight to Hanoi for his first visit - and the issue of ongoing US access to Cam Ranh is expected to surface.
Chinese envoys are watching developments closely, fearing any US-Vietnam move that smacks of containment of a rising China. And future US access to Cam Ranh feeds directly into such fears.
For the third year in a row the resupply ship, USNS Richard E. Byrd, is undergoing 14 days of routine repairs around Cam Ranh. Figures from the US Military Sealift Command show it is the fifth US ship to be repaired in the area since the South China Morning Post first reported the Richard E Byrd's visit in 2010.
The two sides had agreed on four such visits, but the fact that a fifth ship is now being serviced shows some flexibility is already in place.